We demonstrate that MB-treatment attenuates thermally- and pharmacologically-induced heat shock response gene expression, suppressing Hsp70 (HSPA1A) and Hsp27 (HSPB1) upregulation at the mRNA and protein level, and causing chemosensitization of melanoma cells to geldanamycin cytotoxicity. The gene discussed is HSPA1A; the disease is melanoma.