ATF3 and coinfection: To help to identify patients with high susceptibility to HBV–HCV co-infection, we first conducted a meta-analysis among the Asian population and the European population, respectively, then investigated the potential target genes of each novel GWS locus by functional annotation, and finally we focused on potential target genes HMGB1 and ATF3. We found three loci associated with both HBV and HCV infection.