NOX4 and fatty liver disease: One is liver from mice injected with a highly selective GCGR agonist (GSE135881) (Table S1, Supporting Information), which was reported to ameliorate hepatic steatosis.[12] The other is HFD‐induced fatty livers (GSE94754) (Table S2, Supporting Information).[20] As shown in Figure1A, 12 genes exhibited opposite expression changes between the GCGR agonist treatment and the disease model (P value of 0.01 and fold change greater than 1.5 as cutoff points), and among them, two genes of CD9 and NOX4 encode transmembrane proteins.