This concept requires further exploration, ideally with the HCV cell culture (cc) system, rather than the HCVpp system, as cell-to-cell transmission is thought to occur primarily through SR-B1 as well as the tight junction proteins, CLDN1 and OCLN, and following establishment of infection it is highly likely that the infection is propagated via cell-to-cell transmission26,46–49. This evidence concerns the gene CLDN1 and infection.