GADD45A and acute promyelocytic leukemia: In vitiligo melanocytes mRNA quantification demonstrated a significant upregulation of several p53 downstream genes involved in cell cycle regulation such as p21, GADD45a (growth arrest and DNA damage-inducible), PML (promyelocytic leukemia) and a slight increase of the expression of genes involved in p53-mediated apoptosis, such as Bax and Pig-3 (Fig. 3A).