Through the use of the selective inhibitor of survivinYM-155, actually used in phase II clinical trials for advanced non-small cell lungcarcinoma, melanoma, breast and prostate cancer,62 we established that survivin is essential to the occurrenceof the IR-induced plasticity process and sustains both the NS-forming ability and thestem markers overexpression in response to IR. The gene discussed is BIRC5; the disease is melanoma.