It is found that 83% of hepatocellular carcinoma (HCC) tumors possess higher ARID1A expression levels than adjacent normal tissues (16), while in endometrial cancer, the primary tumors have wild-type ARID1A, whereas the metastatic subclones carry deleterious mutations, indicating ARID1A may be required in primary cancers (27). The gene discussed is ARID1A; the disease is hepatocellular carcinoma.