CYP11A1 is also expressed in normal melanocytes and melanoma cells [441,454], so these cells can potentially carry out the CYP11A1-initiated pathways of vitamin D metabolism, with subsequent modification of products by CYP27B1 [407,439], CYP24A1 [438,439], or CYP27A1 [439,440], which are also expressed in melanoma cells [439,441]. The gene discussed is CYP24A1; the disease is melanoma.