Furthermore, the VDR haplotype composed of the C allele of ApaI was a predictor of pegylated-interferon/ribavirin-based therapy failure in chronic hepatitis C (CHC) Caucasian patients (Baur et al., 2012; García-Martín et al., 2013), but not in CHC Asian patients (Hung et al., 2016). Here, VDR is linked to chronic hepatitis C virus infection.