PRRT2 and melanoma: Furthermore, the expression of PKCδ and PKCα was found to be significantly downregulated in PKCα and PKCδ overexpressed (PKCαOV and PKCδOV) melanoma cells respectively, whereas no significant changes in the expression of other PKC isotypes in either of the PKCαOV and PKCδOV melanoma cells were observed (Figure 1D).