PPM1H and hepatocellular carcinoma: The mRNA expression levels of GRP78 and CHOP are downregulated in liver tissues of Atf6Δhep mice, as shown in Figure 1C. However, the mRNA expression levels of GRP78 and CHOP hardly changed in PPM1H-overexpressing Hep-G2 and Huh-7 cells (Figures S5A and S5B), indicating that PPM1H regulated the progression of HCC in a GRP78- and CHOP-independent manner.