- Ubiquitin-like modifier activating enzymes (UBE1)
- Ubiquitin-conjugating enzymes E2 (UBE2)
- Ubiquitin protein ligase E3 component n-recognin (UBR)
- Ubiquitin-specific peptidases (USP)

- UBX domain containing (UBXN)
- UDP glucuronosyltransferases (UGT)
- Voltage-dependent anion channels (VDAC)
- Voltage gated ion channels
- Vomeronasal 1 receptors (VN1R)
- Vomeronasal 2 receptors (VN2R)
- WAS protein homologs (WASH)
- WD repeat domain containing (WDR)
- Wingless-type MMTV integration sites (WNT)
- WW, C2 and coiled-coil domain containing (WWC)
- X-linked mental retardation
- Yip1 domain containing (YIPF)
- Zinc finger, AN1-type domain containing (ZFAND)
- Zinc fingers, BED-type (ZBED)
- Zinc fingers, C2H2 and BTB domain containing (ZBTB)
- Zinc fingers, CCHC domain containing (ZCCHC)
- Zinc fingers, C2H2-type (ZNF)
- Zinc fingers, DHHC-type (ZDHHC)

- Zinc fingers, FYVE domain containing (ZFYVE)
- Zinc fingers, HIT-type (ZNHIT)
- Zinc fingers, matrin-type (ZMAT)
- Zinc fingers, MYM-type (ZMYM)
- Zinc fingers, MYND-type (ZMYND)
- Zinc fingers, RAN binding domain containing (ZRANB)
- Zinc fingers, C2H2 and SCAN domain containing (ZSCAN)
- Zinc fingers, KRAB and SCAN domain containing (ZSCANK)
- Zinc fingers, SWIM-type (ZSWIM)
- Zinc fingers, ZZ-type (ZZZ)