P4HA2 and hepatocellular carcinoma: The results showed that 20 genes, such as TGFBI, FOXA1, EGLN2, OGFOD3, P3H3, P3H1, CALU, P4HA2, HNRNPH2, EGLN3, NCDN, POR, RNF123, ANXA2, HNRNPA1, FAM107B, P4HA1, CDCA3, GEMIN5, and COLGALT1, were mainly related to the regulatory functions of differentially expressed PLOD family genes in HCC patients (Figure 6).