CYP27B1 and melanoma: Neither CPL304110 nor AZD4547 alone had an impact on the expression of CYP27B1, 1α-hydroxylase of 25(OH)D3—a cytochrome essential for a final activation of 1,25(OH)2D3 [25]—however, we noticed a decrease in the mRNA level of CYP27B1 in A375 melanoma cells simultaneously treated with CPL304110 and vitamin D (Figure 5B).