Prompted by our observation that RNF5 is overexpressed and mislocalized to aggregates in muscle biopsies from sIBM patients and deregulated in an animal model for hereditary IBM, we have investigated the role of RNF5 in muscle using 3 genetic mouse models: an inducible transgenic mouse in which the E3 ligase RNF5 is conditionally overexpressed (globally and selectively in skeletal muscle) and an RNF5 KO mouse. Here, RNF5 is linked to inclusion body myositis.