CDKN1A and melanoma: Only 3 genes, P21 (CDKN1A), Growth differentiation factor 15 (GDF15) and Cytoplasmic FMR1 interacting protein 2 (CYFIP2) were commonly regulated in melanocytes and melanoma cells alike and the direction of their regulation (i.e. increased transcript expression of P21 in control shRNA transduced cells) was consistent with their expected regulation by P53 (Table 4).