Figure 2: Model for HBx inhibition of NER. Three protein complexes are involved in DNA-damage recognition in NER pathway, XPA, XPC and RPA (I). These proteins recruits the transcription factor IIH (TFIIH) that incorporate two helicases XPB and XPD that unwind a 30 bp DNA fragment around the DNA damage (II). After DNA unwinding, damaged-DNA strand is excised by XPG and XPF-ERCC1 complex (III). After excision, damaged-DNA strand is removed and replaced by re-synthesizing the template complementary DNA strand by polymerase complex (IV). HBx inhibits NER by inactivating the DNA damagebinding (DDB) protein. HBx also downregulates the expression of XPB and XPD and interfering with TFIIH function leading to accumulation of errors, thereby contributing to HCC development.