However, productive infection was not detected in other hepatic cell lines (e.g. HepG2) [20], non-hepatic cell lines (e.g. HeLa, 293T and U-937) [20] and PBMC (e.g. B and T lymphocytes, monocytes and dendritic cells) [51], likely due to the lack of some entry receptors e.g. claudin-1 and their partner proteins [51] or host factors required for HCV infection e.g. liver specific microRNA miR-122 [52], [53], [54]. The gene discussed is CLDN1; the disease is infection.