| Identifier | Protein names | Gene names | Cross reference refseq | Length | Species |
| P00481 | Ornithine carbamoyltransferase, mitochondrial; EC 2.1.3.3; Ornithine transcarbamylase; OTCase; | Otc; | NP_037210.1; | 354 | rat |
| Q9ERC5 | Otoferlin; Fer-1-like protein 2; | Otof; Fer1l2; | XP_006239895.1; | 1993 | rat |
| Q7M734 | Otopetrin-1; | Otop1; | NP_852098.1; | 600 | rat |
| Q8K560 | Otospiralin; | Otos; | NP_631927.1;XP_008765580.1; | 89 | rat |
| Q32Q05 | Ubiquitin thioesterase OTU1; EC 3.4.19.12; | Yod1; Hshin7; | NP_001008889.1; | 343 | rat |
| B2RYG6 | Ubiquitin thioesterase OTUB1; EC 3.4.19.12; Deubiquitinating enzyme OTUB1; OTU domain-containing ubiquitin aldehyde-binding protein 1; Otubain-1; Ubiquitin-specific-processing protease OTUB1; | Otub1; | NP_001099802.1; | 271 | rat |
| Q2YDU3 | OTU domain-containing protein 5; EC 3.4.19.12; Deubiquitinating enzyme A; DUBA; | Otud5; | NP_001032585.1; | 566 | rat |
| Q63410 | Homeobox protein OTX1; Orthodenticle homolog 1; | Otx1; | NP_037241.1; | 355 | rat |
| Q64201 | Homeobox protein OTX2; Orthodenticle homolog 2; Fragment; | Otx2; | NULL | 70 | rat |
| P56718 | Orexin receptor type 1; Ox-1-R; Ox1-R; Ox1R; Hypocretin receptor type 1; | Hcrtr1; | NP_037196.1; | 416 | rat |
| P83860 | Orexigenic neuropeptide QRFP; P518; [Cleaved into: QRF-amide (Neuropeptide RF-amide) (Pyroglutamylated arginine-phenylalanine-amide peptide)]; | Qrfp; P518; | NP_937843.1;XP_003749488.1;XP_006224405.1;XP_008759893.1; | 124 | rat |
| P04218 | OX-2 membrane glycoprotein; MRC OX-2 antigen; CD antigen CD200; | Cd200; Mox2; | NULL | 278 | rat |
| P56719 | Orexin receptor type 2; Ox-2-R; Ox2-R; Ox2R; Hypocretin receptor type 2; | Hcrtr2; | NP_037206.1; | 460 | rat |
| O35078 | D-amino-acid oxidase; DAAO; DAMOX; DAO; EC 1.4.3.3; | Dao; Dao1; | NP_446078.1; | 346 | rat |
| Q6Y1R5 | 2-oxoglutarate receptor 1; Alpha-ketoglutarate receptor 1; G-protein coupled receptor 80; P2Y purinoceptor 15; P2Y15; | Oxgr1; Gpr80 P2y15; | NP_997471.1;XP_006252533.1; | 337 | rat |
| Q4V8B0 | Oxidation resistance protein 1; Protein C7; | Oxr1; C7; | NP_001184261.1;NP_476494.2; | 839 | rat |
| P70536 | Oxytocin receptor; OT-R; | Oxtr; Otr; | NP_037003.2;XP_006237070.1;XP_008761401.1;XP_008761402.1;XP_008761403.1;XP_008761404.1; | 388 | rat |
| Q4V9H5 | PHD finger protein 20-like protein 1; | Phf20l1; | NP_001258368.1;XP_008763758.1; | 1015 | rat |
| Q6AXZ3 | Serine/threonine-protein phosphatase 2A regulatory subunit B'' subunit gamma; | Ppp2r3c; | NP_001014218.1; | 453 | rat |
| P47824 | P2X purinoceptor 1; P2X1; ATP receptor; Purinergic receptor; RP-2 protein; | P2rx1; | NP_001135839.1;NP_001272344.1;NP_037129.1; | 399 | rat |
