CTLA4 and hepatocellular carcinoma: The results were consistent with those from the GEPIA database analysis and showed that STAT1 was also significantly positively correlated with PD1 (r = 0.48); PD-L1 (r = 0.44); CTLA-4 (r = 0.48); FGFR2 (r = 0.35); FGFR3 (r = 0.32); and IDO1 (r = 0.4) in HCC.