By comparing genomic alterations between primary tumors and recurrent tumors, we identified a gene that was specifically mutated and frequently copy number gained in recurrent tumors, BCL9. BCL9 was mutated in 0.4–2.2% of primary HCC samples in other studies from Japan, South Korea, Europe, and the TCGA cohort,2–7 which also suggested that alterations of BCL9 are especially common in recurrent HCC tumors. The gene discussed is BCL9; the disease is hepatocellular carcinoma.