MTOR and myotonic dystrophy type 1: In myotonic dystrophy type 1 (DM1), a genetic disease that causes myotonia, muscle atrophy, and insulin resistance, insulin receptor type 1 is expressed at lower levels in skeletal muscle, which leads to a decrease in mTOR signaling and an increase in UPS protein expression, giving rise to muscle atrophy (Renna et al., 2019).