Gene annotation revealed a cirrhosis-dependent HBV integration pattern; that is, tumours arising from non-cirrhotic liver displayed a significantly enriched viral integration in the vicinity of putative oncogenes or tumour suppressors such as KMT2B, CCNE1 and AHRR compared with those in the cirrhotic liver (Supplementary Data 5 ), suggesting that constitutive activation or inactivation of these genes may contribute to the early onset of HCC without cirrhotic responses. Here, CCNE1 is linked to neoplasm.