| Identifier | Protein names | Gene names | Cross reference refseq | Length | Species |
| Q6EV70 | GDP-fucose protein O-fucosyltransferase 1; EC 2.4.1.221; Peptide-O-fucosyltransferase 1; O-FucT-1; | Pofut1; Fut12; | NP_001002278.1; | 395 | rat |
| Q8VIJ5 | Protein O-GlcNAcase; OGA; EC 3.2.1.169; Beta-N-acetylhexosaminidase; Beta-hexosaminidase; Bifunctional protein NCOAT; Meningioma-expressed antigen 5; N-acetyl-beta-D-glucosaminidase; EC 3.2.1.52; N-acetyl-beta-glucosaminidase; | Mgea5; Hexc Mea5; | NP_571979.1; | 916 | rat |
| Q5M843 | 2-oxoglutarate and iron-dependent oxygenase domain-containing protein 3; EC 1.14.11.-; | Ogfod3; | NP_001013998.1; | 315 | rat |
| Q9QXY4 | Opioid growth factor receptor; OGFr; Zeta-type opioid receptor; | Ogfr; | NULL | 580 | rat |
| O70249 | N-glycosylase/DNA lyase; EC 4.2.99.18; EC 3.2.2.-; AP lyase; | Ogg1; Mmh Ogh1; | NP_110497.1; | 345 | rat |
| Q4KLH3 | Opioid growth factor receptor-like protein 1; | Ogfrl1; | NP_001020879.1; | 465 | rat |
| P56558 | UDP-N-acetylglucosamine--peptide N-acetylglucosaminyltransferase 110 kDa subunit; EC 2.4.1.255; O-GlcNAc transferase subunit p110; O-linked N-acetylglucosamine transferase 110 kDa subunit; OGT; | Ogt; | NP_058803.2; | 1036 | rat |
| Q6V0K7 | Oncoprotein-induced transcript 3 protein; Liver-specific zona pellucida domain-containing protein; | Oit3; Lzp; | NP_001001507.1; | 546 | rat |
| P23270 | Olfactory receptor 226; Olfactory receptor-like protein I7; | Olr226; | NP_113898.1;XP_006230024.1; | 327 | rat |
| P23267 | Olfactory receptor 287; Olfactory receptor-like protein F6; | Olr287; | NP_775456.1; | 311 | rat |
| P34987 | Olfactory receptor 867; Gustatory receptor GUST27; Olfactory receptor 1172; | Olr867; Olr1172; | NP_001094492.1; | 312 | rat |
| A0JPJ7 | Obg-like ATPase 1; | Ola1; | NP_001029099.1; | 396 | rat |
| P70526 | Olfactory receptor 1; Olfactory receptor 1469; Olfactory receptor HGL-SP1; Olfactory receptor OR5; Olfactory receptor-like protein I54; | Olfr1; Olr1469; | NP_997692.1;XP_003750900.1;XP_008766355.1; | 314 | rat |
| P23272 | Olfactory receptor-like protein I9; | NULL | NULL | 314 | rat |
| Q66H86 | Olfactomedin-like protein 1; | Olfml1; | NP_001013210.1; | 402 | rat |
| B0BNI5 | Olfactomedin-like protein 3; | Olfml3; | NULL | 406 | rat |
| Q9WUQ3 | Oligodendrocyte transcription factor 1; Oligo1; Olg-1 bHLH protein; | Olig1; | NP_068538.2; | 261 | rat |
| O70156 | Oxidized low-density lipoprotein receptor 1; Ox-LDL receptor 1; Lectin-like oxidized LDL receptor 1; LOX-1; Lectin-like oxLDL receptor 1; Lectin-type oxidized LDL receptor 1; [Cleaved into: Oxidized low-density lipoprotein receptor 1, soluble form]; | Olr1; Lox1 Oldlr1; | NP_579840.2; | 364 | rat |
| D3ZS74 | Metalloendopeptidase OMA1, mitochondrial; EC 3.4.24.-; Overlapping with the m-AAA protease 1 homolog; | Oma1; | NP_001100139.1;XP_006238537.1; | 504 | rat |
| Q9Z1S7 | Osteomodulin; Keratan sulfate proteoglycan osteomodulin; KSPG osteomodulin; Osteoadherin; OSAD; | Omd; | NP_114005.1; | 423 | rat |
