ATF6 and hepatocellular carcinoma: To investigate whether hnRNPA2B1 is the mediator of ER stress upregulating PKM2 expression, first, IHC analysis of 72 HCC specimens demonstrated that most HCC patients with a high expression of hnRNPA2B1 also highly express PKM2 (27/38, p = 0.001) and ATF6 (27/38, p = 0.002), PERK (26/38, p = 0.000), GRP78 (23/38, p = 0.032), and IRE1 (31/38, p = 0.000) (Table S2).