| Identifier | Protein names | Gene names | Cross reference refseq | Length | Species |
| Q6P9Z8 | Origin recognition complex subunit 4; | Orc4; Orc4l; | NP_954523.1; | 434 | rat |
| O55232 | Orexin; Hypocretin; Hcrt; [Cleaved into: Orexin-A (Hypocretin-1) (Hcrt1); Orexin-B (Hypocretin-2) (Hcrt2)]; | Hcrt; Ox Ppox; | NP_037311.1; | 130 | rat |
| Q6QI25 | ORM1-like protein 3; Liver regeneration-related protein LRRGT00183; | Ormdl3; | NP_001041362.1;XP_006247407.1;XP_006247408.1; | 153 | rat |
| Q5U1X1 | Oligoribonuclease, mitochondrial; EC 3.1.-.-; RNA exonuclease 2 homolog; Small fragment nuclease; | Rexo2; Smfn; | NP_001008327.1; | 237 | rat |
| Q5RKH6 | Protein OS-9; | Os9; | NP_001007266.1; | 666 | rat |
| Q8K4M9 | Oxysterol-binding protein-related protein 1; ORP-1; OSBP-related protein 1; | Osbpl1a; Orp1; | NP_742020.1; | 950 | rat |
| Q4QQS3 | Protein OSCP1; | Oscp1; | NP_001025094.1; | 379 | rat |
| Q703I1 | Oxidative stress-responsive serine-rich protein 1; Oxidative stress-responsive protein 1; Peroxide-inducible transcript 1 protein; | Oser1; Osr1 Perit1; | NP_963854.1;XP_006235590.1; | 291 | rat |
| Q9WVS2 | Probable tRNA N6-adenosine threonylcarbamoyltransferase; EC 2.6.99.4; N6-L-threonylcarbamoyladenine synthase; t(6)A synthase; O-sialoglycoprotein endopeptidase; t(6)A37 threonylcarbamoyladenosine biosynthesis protein Osgep; tRNA threonylcarbamoyladenosine癷?癸 | Osgep; Gcpl1; | NP_001093980.1; | 335 | rat |
| Q4V7F3 | Probable tRNA N6-adenosine threonylcarbamoyltransferase, mitochondrial; EC 2.6.99.4; N6-L-threonylcarbamoyladenine synthase; t(6)A synthase; O-sialoglycoprotein endopeptidase-like protein 1; t(6)A37 threonylcarbamoyladenosine biosynthesis protein Osgepl1;癷?癸 | Osgepl1; | NP_001019958.1;XP_006244955.1;XP_006244956.1; | 414 | rat |
| Q65Z14 | Oncostatin-M-specific receptor subunit beta; Interleukin-31 receptor subunit beta; IL-31 receptor subunit beta; IL-31R subunit beta; IL-31R-beta; IL-31RB; | Osmr; Osmrb; | NP_001005384.1; | 962 | rat |
| B0K011 | Protein odd-skipped-related 1; | Osr1; Odd1; | NP_001100186.1;XP_006239948.1; | 266 | rat |
| Q6AY34 | Protein odd-skipped-related 2; | Osr2; | NP_001012118.1; | 276 | rat |
| Q641Y0 | Dolichyl-diphosphooligosaccharide--protein glycosyltransferase 48 kDa subunit; DDOST 48 kDa subunit; Oligosaccharyl transferase 48 kDa subunit; EC 2.4.99.18; | Ddost; | NP_001012104.1; | 441 | rat |
| B0BLS0 | Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit 4; | Ost4; | NP_001128162.1;NP_001128163.1; | 37 | rat |
| P04640 | Osteocalcin; Bone Gla protein; BGP; Gamma-carboxyglutamic acid-containing protein; | Bglap; Bglap2; | NP_038200.1;XP_006232656.1; | 99 | rat |
| B0K025 | Oligosaccharyltransferase complex subunit OSTC; | Ostc; Dc2; | NP_001102036.1; | 149 | rat |
| Q6P686 | Osteoclast-stimulating factor 1; | Ostf1; | NP_683690.2;XP_008758509.1; | 214 | rat |
| P61365 | Osteocrin; Musclin; | Ostn; | NP_997495.1;XP_008767023.1;XP_008767025.1; | 132 | rat |
| P08721 | Osteopontin; Bone sialoprotein 1; Secreted phosphoprotein 1; SPP-1; | Spp1; 2b7 Spp-1; | NP_037013.2;XP_008768218.1; | 317 | rat |
