In vitro studies revealed that both calcitriol and EB1089 inhibited TAM-induced upregulation of IRE1α, JNK, Beclin 1, ATG7, LC3BII, and pBcl-2 and increased p62 levels in MCF-7-derived, TAM-resistant LCC9 human breast cancer cells. This evidence concerns the gene ERN1 and breast carcinoma.