Following dex synchronization, the melanoma cells displayed a circadian pattern of drug sensitivity (PJTKCycle < 0.05) in response to an HSP90 inhibitor and also showed rhythmic expression of a subset of Hsp90 genes (Hsp90aa1 and Hsp90ab1) (Fig. 5, A and B). The gene discussed is HSP90AB1; the disease is melanoma.