Although recent studies show that the Ire1‐Xbp1s pathway can promote proliferation of cancer cells in vitro (Ji et al. 2019) and satellite cells in mouse injured muscle (Roy et al. 2021), and pharmacological activation of ER stress stimulates β cell proliferation in vitro, the mechanism connecting ER stress response and cell proliferation remains unclear (Sharma et al. 2015). This evidence concerns the gene ERN1 and cancer.