A nevus GWAS meta-analysis shows that variants in MTAP, PLA2G6, IRF4, KITLG and the 9q32 region affect nevus count (38); combining this with a meta-analysis (41) of melanoma GWAS studies showed that GPRC5A, CYP1B1, PPARGC1B, HDAC4, FAM208B, DOCK8, and SYNE2 were associated with nevus count as well as melanoma risk. The gene discussed is CYP1B1; the disease is nevus.