IFNA1 and chronic hepatitis B virus infection: Previous data about this VDR SNP in association with treatment outcomes in other infectious diseases showed that the allele A of ApaI was considered the pretreatment genetic predictor of sustained hepatitis B surface antigen (HBsAg) and loss in hepatitis B early antigen (HBeAg) in patients with chronic hepatitis B with pegylated interferon (Peg-IFN) monotherapy (Shan et al., 2019).