DHCR7 and chronic hepatitis C virus infection: The present study shows that genetic variations in CYP2R1, GC, and DHCR7 are associated with progression to HCC in patients with chronic hepatitis C. The SNPs investigated in CYP2R1, GC, and DHCR7 have been identified by two independent GWAS as relevant genetic determinants of reduced 25(OH)D3 serum levels [8], [9].