Chimeric HBx/MLL4 fusion transcripts containing the HBx promoter and Open Reading Frame (ORF)fused to the exon 4 and 5 of MLL4 were initially detected in 4 of 10 HCC patients [76] and subsequently confirmed in later studies and reported to lead to increased MLL4 expression [17, 18, 67]. This evidence concerns the gene KMT2B and hepatocellular carcinoma.