More importantly, initial clinical trials with the HSP90 inhibitors tanespimycin (17-AAG) and alvespimycin (17-DMAG), two derivatives of the antibiotic geldanamycin, provided additional lines of evidence that supports the validity of targeting HSP90 in ErbB2-positive breast cancers [16, 17]. The gene discussed is ERBB2; the disease is breast carcinoma.