PDXK and hepatocellular carcinoma: established a cuproptosis‐related signature involving five CRGs‐solute carrier family 25 member 28, pyridoxal kinase (PDXK), C‐type lectin domain family 3 member B, hepsin, and ring finger protein, transmembrane 1 and observed significantly upregulated expression of PDXK in HCC tissues.