CYP1A1 and hepatocellular carcinoma: Functional experiments using FTH1‐knockdown/−overexpressing HCC cell lines and xenograft models demonstrated that FTH1 enhances proliferation, migration, and tumour growth by upregulating CYP1A1/CYP1A2 in the tryptophan pathway, thereby increasing the synthesis of 6‐hydroxymelatonin (6‐HMT).