TFRC and lysosomal storage disease: This is particularly relevant for lysosomal storage disorders (LSDs), for which traditional high-affinity, bivalent TfR-binding antibody fusions and newer monovalent TfR-binding TV-fusions are currently being evaluated in the clinic (NCT04251026, 2022; Okuyama et al., 2019; Okuyama et al., 2021).