TJP2 and progressive familial intrahepatic cholestasis: Although an increasing number of pathogenic variants have been revealed in the TJP2 gene (Vitale et al., 2018; Wei et al., 2020; Zhang et al., 2020a), the molecular mechanism by which those variants cause PFIC needed to be further characterized (Sambrotta and Thompson, 2015; Amirneni et al., 2020).