HSP90AA1 and neoplasm: Several anticancer drugs, such as geldanamycin and radicicol, inhibit the activity of HSP90 by binding to the ATP-binding site of the HSP90 NTD, leading to the abnormal folding of HSP90 client proteins and inhibiting tumor growth (Supko et al., 1995 ▸; Sydor et al., 2006 ▸; Biebl & Buchner, 2019 ▸).