- 2',5'-Oligoadenylate Synthetase Like Protein (OASL)
- Odorant Binding Protein 2B (OBP2B)
- Outer Dense Fiber Protein 3, Sperm Tails (ODF3)
- Outer Dense Fiber Protein 4, Sperm Tails (ODF4)
- Outer Dense Fiber Protein 2, Sperm Tails (ODF2)
- Oligodendrocyte Transcription Factor 1 (OLIG1)
- Oxysterol Binding Protein Like Protein 1A (OSBPL1A)
- Oxysterol Binding Protein Like Protein 2 (OSBPL2)
- Oxysterol Binding Protein Like Protein 3 (OSBPL3)
- Oxysterol Binding Protein Like Protein 5 (OSBPL5)
- Oxysterol Binding Protein Like Protein 8 (OSBPL8)
- Oxysterol Binding Protein Like Protein 6 (OSBPL6)
- Oxysterol Binding Protein Like Protein 7 (OSBPL7)
- Oxysterol Binding Protein 2 (OSBP2)
- Organic Solute Transporter Alpha (OSTa)
