CDKN2A and melanoma: Previous reports have showed that EZH2 is involved in the regulation of senescence in human progenitor cells, as well as mouse embryonic fibroblasts (MEFs) through inhibition of INK4b (p16) and INK4a (p15) locus.14, 15 Also, EZH2 depletion causes senescence of melanoma cells.16 As LDM is found to induce senescence in tumor cells with yet undefined mechanism,17 we speculate that EZH2 may be involved in the regulation of LDM-induced senescence.