| Sperm motility kinase Y (EC 2.7.11.1) | Gm7168 | A0AUV4 | 1 |
| Sperm-associated antigen 1 (Infertility-related sperm protein Spag-1) (TPR-containing protein involved in spermatogenesis) (TPIS) | Spag1 Tpis | Q80ZX8 | 1 |
| Sperm-associated antigen 5 (Mastrin) (Mitotic spindle-associated protein p126) (MAP126) | Spag5 | Q7TME2 | 1 |
| Spermatid-specific heat shock protein 70 (Fragment) | Hsc70t | Q9R2A1 | 1 |
| Spermatogenesis-associated protein 19, mitochondrial (Spermatogenic cell-specific gene 1 protein) (Spergen-1) | Spata19 Spergen1 | Q9DAQ9 | 1 |
| Spermatogenesis-associated protein 2-like protein (SPATA2-like protein) | Spata2l Kiaa4138 | Q8BNN1 | 1 |
| Spermatogenesis-associated protein 20 (Sperm-specific protein 411) (Ssp411) (Transcript increased in spermiogenesis 78 protein) | Spata20 Tisp78 | Q80YT5 | 1 |
| Sphingomyelin phosphodiesterase 2 (EC 3.1.4.12) (Lyso-platelet-activating factor-phospholipase C) (Lyso-PAF-PLC) (Neutral sphingomyelinase) (N-SMase) (nSMase) | Smpd2 | O70572 | 1 |
| Sphingomyelin phosphodiesterase 3 (EC 3.1.4.12) (Neutral sphingomyelinase 2) (nSMase-2) (nSMase2) (Neutral sphingomyelinase II) | Smpd3 | Q9JJY3 | 1 |
| Sphingomyelin phosphodiesterase 4 | Smpd4 | E9Q1V5 | 1 |
| Sphingomyelin phosphodiesterase 4 | Smpd4 | E9Q914 | 1 |
| Sphingomyelin phosphodiesterase 4 | Smpd4 | E9Q9L1 | 1 |
| Sphingomyelin phosphodiesterase 4 | Smpd4 | E9Q0L7 | 1 |
| Sphingomyelin phosphodiesterase 4 (EC 3.1.4.12) (Neutral sphingomyelinase 3) (nSMase-3) (nSMase3) (Neutral sphingomyelinase III) | Smpd4 Kiaa1418 | Q6ZPR5 | 1 |
| Sphingosine kinase 1 (SK 1) (SPK 1) (EC 2.7.1.91) | Sphk1 | Q8CI15 | 1 |
| Sphingosine kinase 2 (SK 2) (SPK 2) (EC 2.7.1.91) | Sphk2 | Q9JIA7 | 1 |
| Spindle assembly abnormal protein 6 homolog | Sass6 Sas6 | Q80UK7 | 1 |
| Splicing factor 3A subunit 2 (Splicing factor 3a, subunit 2, isoform CRA_c) | Sf3a2 mCG_12094 | D3YW09 | 1 |
| Splicing factor 45 (Fragment) | Rbm17 | A2AP40 | 1 |
| Splicing factor ESS-2 homolog (ES2 protein) (Expressed sequence 2 embryonic lethal) | Ess2 Dgcr14 Dgsi Es2 Es2el | O70279 | 1 |
| Splicing factor, suppressor of white-apricot homolog (Splicing factor, arginine/serine-rich 8) (Suppressor of white apricot protein homolog) | Sfswap Sfrs8 Srsf8 Swap | Q3USH5 | 1 |
| Spondin-1 (F-spondin) | Spon1 | Q8VCC9 | 1 |
| Spondin-2 (Mindin) | Spon2 | Q8BMS2 | 1 |
| Squalene monooxygenase (EC 1.14.14.17) (Squalene epoxidase) (SE) | Sqle Erg1 | P52019 | 1 |
| SR-related CTD-associated factor 11 | Scaf11 | E9PZM7 | 1 |
| SRC kinase signaling inhibitor 1 (SNAP-25-interacting protein) (SNIP) (p130Cas-associated protein) (p140Cap) | Srcin1 Kiaa1684 P140 | Q9QWI6 | 1 |
| Stabilin-1 (Fasciclin, EGF-like, laminin-type EGF-like and link domain-containing scavenger receptor 1) (FEEL-1) | Stab1 Feel1 | Q8R4Y4 | 1 |
| Stanniocalcin-2 (STC-2) | Stc2 | O88452 | 1 |
| StAR-related lipid transfer protein 4 (START domain-containing protein 4) (StARD4) | Stard4 | Q99JV5 | 1 |
| StAR-related lipid transfer protein 9 (Kinesin-like protein Kif16a) (START domain-containing protein 9) (StARD9) | Stard9 Kiaa1300 Kif16a | Q80TF6 | 1 |
| START domain-containing protein 10 | Stard10 | E9PVP0 | 1 |
| Stathmin | Stmn1 | D3Z5N2 | 1 |
| Stathmin domain-containing protein 1 | Stmnd1 Gm1574 | Q6P3A1 | 1 |
| Stathmin-2 (Superior cervical ganglion-10 protein) (Protein SCG10) | Stmn2 Scg10 Scgn10 Stmb2 | P55821 | 1 |
| Sterile alpha motif domain-containing protein 9-like (SAM domain-containing protein 9-like) | Samd9l Kiaa2005 | Q69Z37 | 1 |
| Steroid hormone receptor ERR1 (Estrogen receptor-like 1) (Estrogen-related receptor alpha) (ERR-alpha) (Nuclear receptor subfamily 3 group B member 1) | Esrra Err1 Estrra Nr3b1 | O08580 | 1 |
| Steroid receptor RNA activator 1 (Fragment) | Sra1 | G3X8R2 | 1 |
| Steroid receptor RNA activator 1 (Steroid receptor RNA activator protein) (SRAP) | Sra1 | Q80VJ2 | 1 |
| Steryl-sulfatase (EC 3.1.6.2) (Arylsulfatase C) (ASC) (Steroid sulfatase) (Steryl-sulfate sulfohydrolase) | Sts | P50427 | 1 |
| Striated muscle-specific serine/threonine-protein kinase | Speg | E9QQ25 | 1 |
| Stromal cell-derived factor 2 (SDF-2) | Sdf2 | Q9DCT5 | 1 |
| Stromal interaction molecule 2 | Stim2 Kiaa1482 | P83093 | 1 |
| Stromal interaction molecule 2 | Stim2 | I1E4X8 | 1 |
| Stromelysin-2 (SL-2) (EC 3.4.24.22) (Matrix metalloproteinase-10) (MMP-10) (Transin-2) | Mmp10 | O55123 | 1 |
| Stromelysin-3 (SL-3) (ST3) (EC 3.4.24.-) (Matrix metalloproteinase-11) (MMP-11) | Mmp11 | Q02853 | 1 |
| Structural maintenance of chromosomes protein 1B (SMC protein 1B) (SMC-1-beta) (SMC-1B) | Smc1b Smc1l2 | Q920F6 | 1 |
| Structural maintenance of chromosomes protein 6 (SMC protein 6) (SMC-6) (mSMC6) | Smc6 Kiaa4103 Smc6l1 | Q924W5 | 1 |
| Sulfatase-modifying factor 1 | Sumf1 | E9Q0Z7 | 1 |
| Sulfatase-modifying factor 1 | Sumf1 | E9Q265 | 1 |
| Sulfatase-modifying factor 2 (C-alpha-formylglycine-generating enzyme 2) | Sumf2 | Q8BPG6 | 1 |
| Sulfate transporter (Diastrophic dysplasia protein homolog) (ST-OB) (Solute carrier family 26 member 2) | Slc26a2 Dtd Dtdst | Q62273 | 1 |
| Sulfate transporter (Fragment) | Slc26a2 | E9PZ06 | 1 |
| Sulfotransferase (EC 2.8.2.-) | Sult1a1 | D3Z3G5 | 1 |
| Sulfotransferase (EC 2.8.2.-) (Fragment) | Hs3st1 | D3YUR4 | 1 |
| Sulfotransferase 1 family member D1 (ST1D1) (EC 2.8.2.-) (Amine N-sulfotransferase) (SULT-N) (Dopamine sulfotransferase Sult1d1) (Tyrosine-ester sulfotransferase) | Sult1d1 St1d1 | Q3UZZ6 | 1 |
| SUMO-conjugating enzyme (EC 2.3.2.-) (Fragment) | Ube2i | G3UYP0 | 1 |
| SUN domain-containing ossification factor (Membrane protein CH1) (Protein osteopotentia) (SUN-like protein 1) | Suco Opt | Q8C341 | 1 |
| Suppressor of cytokine signaling 7 (SOCS-7) | Socs7 Cish7 Nap4 | Q8VHQ2 | 1 |
| Suppressor of IKBKE 1 (Suppressor of IKK-epsilon) | Sike1 | Q9CPR7 | 1 |
| Surfeit locus protein 1 | Surf1 Surf-1 | P09925 | 1 |
| Surfeit locus protein 4 | Surf4 | E0CXD9 | 1 |
| SURP and G-patch domain-containing protein 1 (Splicing factor 4) | Sugp1 Sf4 | Q8CH02 | 1 |
| Sushi-repeat-containing protein SRPX (DRS protein) | Srpx | Q9R0M3 | 1 |
| SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A-like protein 1 (EC 3.6.4.-) (HepA-related protein) (mharp) (Sucrose nonfermenting protein 2-like 1) | Smarcal1 Harp | Q8BJL0 | 1 |
| SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (Fragment) | Smarcb1 | F6U415 | 1 |
| SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily E member 1-related (SMARCE1-related protein) (BRCA2-associated factor 35) (HMG box-containing protein 20B) (Structural DNA-binding protein BRAF35) | Hmg20b Braf35 Hmgx2 Smarce1r | Q9Z104 | 1 |
| Symplekin | Sympk | F8WJD4 | 1 |
| Synapsin-1 (Synapsin I) | Syn1 Syn-1 | O88935 | 1 |
| Synapsin-2 (Synapsin II) | Syn2 | Q64332 | 1 |
| Synapsin-3 (Synapsin III) | Syn3 | Q8JZP2 | 1 |
| Synaptic functional regulator FMR1 | Fmr1 | D3Z6U8 | 1 |
| Synaptic functional regulator FMR1 | Fmr1 | E9QAS8 | 1 |
| Synaptic functional regulator FMR1 | Fmr1 | E9QAT0 | 1 |
| Synaptic functional regulator FMR1 | Fmr1 | E9QNF5 | 1 |
| Synaptogyrin-3 | Syngr3 | Q8R191 | 1 |
| Synaptojanin-1 | Synj1 | E9Q7S0 | 1 |
| Synaptojanin-1 (Fragment) | Synj1 | D3Z1M7 | 1 |
| Synaptojanin-1 (Fragment) | Synj1 | F7BQW7 | 1 |
| Synaptojanin-2 | Synj2 | F8WHD8 | 1 |
| Synaptojanin-2 (Fragment) | Synj2 | D3Z6E7 | 1 |
| Synaptojanin-2-binding protein (Activin receptor-interacting protein 2) (Activin receptor-interacting protein 4) (Mitochondrial outer membrane protein 25) | Synj2bp Arip2 Omp25 | Q9D6K5 | 1 |
| Synaptonemal complex protein 1 (SCP-1) | Sycp1 Scp1 | Q62209 | 1 |
| Synaptonemal complex protein 2 (SCP-2) (Synaptonemal complex lateral element protein) | Sycp2 Scp2 | Q9CUU3 | 1 |
| Synaptonemal complex protein 3 (SCP-3) | Sycp3 Scp3 | P70281 | 1 |
| Synaptopodin | Synpo | E9Q3E2 | 1 |
| Synaptosomal-associated protein 47 | Snap47 | B2FDF6 | 1 |
| Synaptotagmin-11 (Fragment) | Syt11 | S4R1M8 | 1 |
| Synaptotagmin-7 (Synaptotagmin VII) (SytVII) | Syt7 | Q9R0N7 | 1 |
| Syndecan-3 (SYND3) | Sdc3 Kiaa0468 | Q64519 | 1 |
| Syntaxin 4A (placental) | Stx4a | D6RJ29 | 1 |
| Syntaxin 5A | Stx5a | H3BKJ7 | 1 |
| Syntaxin-16 | Stx16 | F6X4N5 | 1 |
| Syntaxin-16 (Fragment) | Stx16 | B7ZCB8 | 1 |
| Syntaxin-1B | Stx1b Stx1b1 Stx1b2 | P61264 | 1 |
| Syntaxin-2 (Fragment) | Stx2 | D3YY94 | 1 |
| Syntaxin-3 | Stx3 Stx3a | Q8R1B7 | 1 |
| Syntaxin-3 | Stx3 | A0A1C7CYU4 | 1 |
| Syntenin | Sdcbp | O88601 | 1 |
| T-cell receptor beta-2 chain C region | 0 | P01851 | 1 |
| T-cell surface glycoprotein CD3 gamma chain (T-cell receptor T3 gamma chain) (CD antigen CD3g) | Cd3g | P11942 | 1 |