PTTG1 and hepatocellular carcinoma: In HCC tissues, TNF‐α mRNA expression was positively correlated with PTTG1 mRNA expression (R2 = 0.62, P < .01) (Figure 4D; Figure S1B), while in paracancer tissues, TNF‐α mRNA levels had no significant correlation with PTTG1 mRNA levels (R2 = 0.02, P = .52) (Figure S1C).