| Tyrosine-protein phosphatase non-receptor type 3 (EC 3.1.3.48) | Ptpn3 | A2ALK8 | 1 |
| Tyrosine-protein phosphatase non-receptor type substrate 1 | Sirpa | E0CYM8 | 1 |
| U1 small nuclear ribonucleoprotein A (Fragment) | Snrpa | D3Z0S6 | 1 |
| U2 small nuclear ribonucleoprotein B'' (Fragment) | Snrpb2 | A2CES4 | 1 |
| U3 small nucleolar ribonucleoprotein protein MPP10 (M phase phosphoprotein 10) | Mphosph10 | Q810V0 | 1 |
| U4/U6.U5 small nuclear ribonucleoprotein 27 kDa protein (U4/U6.U5 snRNP 27 kDa protein) (U4/U6.U5-27K) (U4/U6.U5 tri-snRNP-associated protein 3) | Snrnp27 | Q8K194 | 1 |
| U6 snRNA-associated Sm-like protein LSm3 | Lsm3 | P62311 | 1 |
| U6 snRNA-associated Sm-like protein LSm5 | Lsm5 | P62322 | 1 |
| U6 snRNA-associated Sm-like protein LSm6 | Lsm6 | P62313 | 1 |
| U6 snRNA-associated Sm-like protein LSm7 | Lsm7 | Q9CQQ8 | 1 |
| U7 snRNA-associated Sm-like protein LSm11 | Lsm11 | Q8BUV6 | 1 |
| U8 snoRNA-decapping enzyme (EC 3.6.1.62) (IDP phosphatase) (IDPase) (EC 3.6.1.64) (Inosine diphosphate phosphatase) (Nucleoside diphosphate-linked moiety X motif 16) (Nudix motif 16) (m7GpppN-mRNA hydrolase) | Nudt16 | Q6P3D0 | 1 |
| UAP56-interacting factor (Forty-two-three domain-containing protein 1) (Protein 40-2-3) | Fyttd1 Uif | Q91Z49 | 1 |
| Ubiquinol-cytochrome-c reductase complex assembly factor 2 | Uqcc2 2900010M23Rik Mnf1 | D3Z4C9 | 1 |
| Ubiquinol-cytochrome-c reductase complex assembly factor 2 | Uqcc2 2900010M23Rik Mnf1 | D3Z4D6 | 1 |
| Ubiquinol-cytochrome-c reductase complex assembly factor 2 (Mitochondrial nucleoid factor 1) (Mitochondrial protein M19) | Uqcc2 Mnf1 | Q9CQY6 | 1 |
| Ubiquinone biosynthesis protein COQ4 homolog, mitochondrial (Coenzyme Q biosynthesis protein 4 homolog) | Coq4 | Q8BGB8 | 1 |
| Ubiquinone biosynthesis protein COQ4 homolog, mitochondrial (Fragment) | Coq4 | B7ZCV4 | 1 |
| Ubiquinone biosynthesis protein COQ9, mitochondrial | Coq9 | Q8K1Z0 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 17-like protein B (USP17-B) (EC 3.4.19.12) (Deubiquitinating enzyme 1A) | Usp17lb Dub1a | E9Q9U0 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 19 | Usp19 | E9Q9M5 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 19 (Ubiquitin specific peptidase 19, isoform CRA_a) | Usp19 mCG_16487 | J3KMM1 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 24 | Usp24 | E9PV45 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 26 (EC 3.4.19.12) (Deubiquitinating enzyme 26) (Ubiquitin thioesterase 26) (Ubiquitin-specific-processing protease 26) | Usp26 | Q99MX1 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 28 (EC 3.4.19.12) (Deubiquitinating enzyme 28) (Ubiquitin thioesterase 28) (Ubiquitin-specific-processing protease 28) | Usp28 Kiaa1515 | Q5I043 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 33 (EC 3.4.19.12) (Deubiquitinating enzyme 33) (Ubiquitin thioesterase 33) (Ubiquitin-specific-processing protease 33) (VHL-interacting deubiquitinating enzyme 1) | Usp33 Vdu1 | Q8R5K2 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 34 (Fragment) | Usp34 | F6WJB7 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 40 (EC 3.4.19.12) (Deubiquitinating enzyme 40) (Ubiquitin thioesterase 40) (Ubiquitin-specific-processing protease 40) | Usp40 | Q8BWR4 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 46 (Fragment) | Usp46 | D3YVJ5 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 48 | Usp48 | A2ALR9 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 48 (EC 3.4.19.12) (Deubiquitinating enzyme 48) (Ubiquitin thioesterase 48) (Ubiquitin-specific-processing protease 48) | Usp48 Kiaa4202 | Q3V0C5 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 7 | Usp7 | F8VPX1 | 1 |
| Ubiquitin carboxyl-terminal hydrolase 8 | Usp8 | A2AI52 | 1 |
| Ubiquitin carboxyl-terminal hydrolase CYLD | Cyld | Z4YJJ5 | 1 |
| Ubiquitin conjugation factor E4 B | Ube4b | G3UZD6 | 1 |
| Ubiquitin domain-containing protein UBFD1 | Ubfd1 D7Wsu128e | Q78JW9 | 1 |
| Ubiquitin thioesterase OTUB2 (Fragment) | Otub2 | F6SXD2 | 1 |
| Ubiquitin-activating enzyme E1, Chr X (Ubiquitin-like modifier activating enzyme 1) | Uba1 Ube1x mCG_126518 | B9EHN0 | 1 |
| Ubiquitin-associated domain-containing protein 2 (UBA domain-containing protein 2) (Phosphoglycerate dehydrogenase-like protein 1) | Ubac2 Phgdhl1 | Q8R1K1 | 1 |
| Ubiquitin-associated protein 2 | Ubap2 | A2AMY5 | 1 |
| Ubiquitin-associated protein 2 (Fragment) | Ubap2 | F6PYV5 | 1 |
| Ubiquitin-associated protein 2 (UBAP-2) (Protein lingerer homolog 1) (mLig-1) | Ubap2 Lig1 | Q91VX2 | 1 |
| Ubiquitin-conjugating enzyme E2 D1 (EC 2.3.2.23) ((E3-independent) E2 ubiquitin-conjugating enzyme D1) (EC 2.3.2.24) (E2 ubiquitin-conjugating enzyme D1) (Ubiquitin carrier protein D1) (Ubiquitin-conjugating enzyme E2(17)KB 1) (Ubiquitin-conjugating enzyme E2-17 kDa 1) (Ubiquitin-protein ligase D1) | Ube2d1 | P61080 | 1 |
| Ubiquitin-conjugating enzyme E2 E1 (EC 2.3.2.23) ((E3-independent) E2 ubiquitin-conjugating enzyme E1) (EC 2.3.2.24) (E2 ubiquitin-conjugating enzyme E1) (UbcM3) (Ubiquitin carrier protein E1) (Ubiquitin-protein ligase E1) | Ube2e1 Ubce5 Ubcm3 | P52482 | 1 |
| Ubiquitin-conjugating enzyme E2 E2 (EC 2.3.2.23) (E2 ubiquitin-conjugating enzyme E2) (Ubiquitin carrier protein E2) (Ubiquitin-protein ligase E2) | Ube2e2 | Q91W82 | 1 |
| Ubiquitin-conjugating enzyme E2 E2 (Fragment) | Ube2e2 | D3YXD1 | 1 |
| Ubiquitin-conjugating enzyme E2 E2 (Fragment) | Ube2e2 | H3BL23 | 1 |
| Ubiquitin-conjugating enzyme E2 E2 (Fragment) | Ube2e2 | H3BL69 | 1 |
| Ubiquitin-conjugating enzyme E2 E3 (EC 2.3.2.23) (E2 ubiquitin-conjugating enzyme E3) (UbcM2) (Ubiquitin carrier protein E3) (Ubiquitin-conjugating enzyme E2-23 kDa) (Ubiquitin-protein ligase E3) | Ube2e3 Ubce4 Ubcm2 | P52483 | 1 |
| Ubiquitin-conjugating enzyme E2 K | Ube2k | D3Z4U3 | 1 |
| Ubiquitin-conjugating enzyme E2 L3 | Ube2l3 | D3YZS3 | 1 |
| Ubiquitin-conjugating enzyme E2 Q2 | Ube2q2 | D3Z647 | 1 |
| Ubiquitin-conjugating enzyme E2 Q2 (EC 2.3.2.23) (E2 ubiquitin-conjugating enzyme Q2) (Ubiquitin carrier protein Q2) (Ubiquitin-protein ligase Q2) | Ube2q2 | Q8K2Z8 | 1 |
| Ubiquitin-conjugating enzyme E2 R1 (EC 2.3.2.23) ((E3-independent) E2 ubiquitin-conjugating enzyme R1) (EC 2.3.2.24) (E2 ubiquitin-conjugating enzyme R1) (Ubiquitin-conjugating enzyme E2-32 kDa complementing) (Ubiquitin-conjugating enzyme E2-CDC34) (Ubiquitin-protein ligase R1) | Cdc34 Ubch3 Ube2r1 | Q8CFI2 | 1 |
| Ubiquitin-conjugating enzyme E2 variant 1 | Ube2v1 | B7ZBY7 | 1 |
| Ubiquitin-conjugating enzyme E2 variant 1 (Fragment) | Ube2v1 | B7ZBY6 | 1 |
| Ubiquitin-conjugating enzyme E2 variant 2 (Ubiquitin-conjugating enzyme E2 variant 2, isoform CRA_b) | Ube2v2 mCG_126823 | A6X925 | 1 |
| Ubiquitin-fold modifier-conjugating enzyme 1 (Ufm1-conjugating enzyme 1) | Ufc1 | Q9CR09 | 1 |
| Ubiquitin-like domain-containing CTD phosphatase 1 (EC 3.1.3.16) (Nuclear proteasome inhibitor UBLCP1) | Ublcp1 | Q8BGR9 | 1 |
| Ubiquitin-like protein 5 | Ubl5 | E0CZB3 | 1 |
| Ubiquitin-like protein FUBI (Monoclonal non-specific suppressor factor beta) (MNSF-beta) | Fau | P35545 | 1 |
| Ubiquitin-protein ligase E3A (EC 2.3.2.26) (HECT-type ubiquitin transferase E3A) (Oncogenic protein-associated protein E6-AP) | Ube3a | E9QKT1 | 1 |
| Ubiquitin-protein ligase E3B (EC 2.3.2.26) (HECT-type ubiquitin transferase E3B) | Ube3b | Q9ES34 | 1 |
| Ubiquitin-related modifier 1 | Urm1 | Q9D2P4 | 1 |
| Ubiquitin-specific peptidase 31 | Usp31 | E9Q6Y8 | 1 |
| UDP-glucose 4-epimerase (EC 5.1.3.2) (Galactowaldenase) (UDP-N-acetylglucosamine 4-epimerase) (UDP-GlcNAc 4-epimerase) (EC 5.1.3.7) (UDP-galactosamine 4-epimerase) (UDP-GalNAc 4-epimerase) (UDP-galactose 4-epimerase) | Gale | Q8R059 | 1 |
| UDP-glucuronosyltransferase 1-7C (UDPGT 1-7C) (UGT1*7C) (UGT1-07C) (UGT1.7C) (EC 2.4.1.17) (UDP-glucuronosyltransferase 1A7C) (UGT1A10) | Ugt1a7c Ugt1a10 | Q6ZQM8 | 1 |
| Ufm1-specific protease 2 (UfSP2) (EC 3.4.22.-) | Ufsp2 | Q99K23 | 1 |
| UMAP1-MVP12-associated (UMA) domain-containing 1 (Fragment) | Umad1 Gm16039 | E0CZ61 | 1 |
| Uncharacterized family 31 glucosidase KIAA1161 (EC 3.2.1.-) | Kiaa1161 | Q69ZQ1 | 1 |
| Uncharacterized protein | Gm27029 | A2A4P3 | 1 |
| Uncharacterized protein | Gm27029 | A2A4P4 | 1 |
| Uncharacterized protein | Gm15128 | A2ADW8 | 1 |
| Uncharacterized protein | Gm10439 | A2AJU2 | 1 |
| Uncharacterized protein | Gm13697 Gm13691 Gm13693 Gm13694 Gm13696 Gm13698 | A2AK42 | 1 |
| Uncharacterized protein | Gm13695 | A2AK44 | 1 |
| Uncharacterized protein | Gm15080 | A2BI02 | 1 |
| Uncharacterized protein | Gm15093 | A2BI72 | 1 |
| Uncharacterized protein | Gm15127 | B1AVZ5 | 1 |
| Uncharacterized protein | Gm15091 | B1AZM2 | 1 |
| Uncharacterized protein | Gm15107 | B1B0X0 | 1 |
| Uncharacterized protein | Gm15114 | B1B0X6 | 1 |
| Uncharacterized protein | Gm20521 Pabpn1 | D3Z5F7 | 1 |
| Uncharacterized protein | Gm20498 | E9PVN6 | 1 |
| Uncharacterized protein | Gm20431 | E9PY39 | 1 |
| Uncharacterized protein | Gm15127 Gm15128 | E9Q1L3 | 1 |
| Uncharacterized protein | Gm15800 | E9Q2E4 | 1 |
| Uncharacterized protein | Gm20518 Dgcr2 | E9Q548 | 1 |
| Uncharacterized protein | Gm15097 | E9QA14 | 1 |
| Uncharacterized protein | Gm21992 | F7BGR7 | 1 |
| Uncharacterized protein | Gm6768 | J3QND8 | 1 |
| Uncharacterized protein | Gm15097 | L7MU67 | 1 |
| Uncharacterized protein | Gm15294 | V9GXA7 | 1 |
| Uncharacterized protein | Gm28036 | V9GXJ1 | 1 |
| Uncharacterized protein | Gm13695 | J3QM48 | 1 |
| Uncharacterized protein | Gm13698 Gm13693 Gm13694 Gm13696 Gm13697 | J3QNR0 | 1 |
| Uncharacterized protein | Gm5039 | J3QNT6 | 1 |
| Uncharacterized protein | Gm37240 | E9QAY5 | 1 |
| Uncharacterized protein | Gm17428 | F6XET4 | 1 |
| Uncharacterized protein | Gm8444 | F6XS56 | 1 |