HMCN1 and epidermolysis bullosa simplex: Given that (1) HMCN1 variants associated with EBS severity affect protein domains likely to be responsible for regulating protein binding (Fig. 2), (2) human hemicentin-1 is expressed at the BMZ (Fig. 3), and (3) hemicentin-1 has been shown to bind various components of the BMZ and to play an important role in maintaining BMZ stability in other tissues and species (Gianakas et al., 2023; Welcker et al., 2021), we hypothesized that human hemicentin-1 binds components of the BMZ that are relevant to both BMZ integrity and EBS pathogenesis.