P4HB and neoplasm: Silencing of PDIA6 or PDIA4 by RNA interferences or treatment with a small molecule inhibitor of the protein disulfide isomerases in TNBC cells successfully recapitulated the ipomoeassin F phenotypes, including the induction of ER stress, UPR and autophagy, suggesting that the reduction of PDIAs is the key mediator of the pharmacological effects of ipomoeassin F. Moreover, ipomoeassin F significantly suppressed TNBC growth in a mouse tumor xenograft model, with a marked reduction in PDIA6 and PDIA4 levels in the tumor samples.