A wide range of ER stress‐related genes, such as HSP90B1, HSPA5, CALR, and DNAJC3, and the bona fide UPR genes DDIT3, ATF4, EIF2AK3, ERN1, PPP1R15A, and the spliced form of XBP1 were upregulated in HGPS patient cells (Fig 2D). Here, EIF2AK3 is linked to Hutchinson-Gilford progeria syndrome.