The discovery of these novel derivatives demonstrated that resorcinol-based inhibitors have large potential for the further investigation into the development of anti-tumor drugs.437 Recently, a series of HSP90 inhibitor containing the aryl-resorcinol scaffold were designed and investigated the SARs, elucidating the dissimilarity in ligand selectivity between the isoforms of HSP90.438 Compound 30 f, a novel benzamide derivative, was discovered in 2018 and showed high HSP90 binding affinity (IC50 = 5.3 nM). Here, HSP90AB1 is linked to neoplasm.