Plumbagin Triggers Cuproptosis in Hepatocellular Carcinoma (HCC) via the DNA‐Methyltransferase 1 (DNMT1)/microRNA‐302a‐3p (miR‐302a‐3p)/ATPase Copper Transporting Beta (ATP7B) Axis. This evidence concerns the gene ATP7B and hepatocellular carcinoma.