IFNG and biliary atresia: Due to the large number of CpG islands in its promoter region serving as sites for methylation, the IFN-γ gene is a methylation-sensitive gene9–11 Studies have shown that 5-aza-2′-deoxycytidine (5-aza-dC) inhibition of methylation could establish biliary atresia, and that bile duct injury is closely related to IFN-γ expression in a zebrafish model12.