Drug resistance in MM is connected to both adjustments in MM cells (i.e., the upregulation of Pgp [98], the mutation in the proteasomal system [95], changes in CD expression [99]) and the microenvironmental adaptations (environment-mediated drug resistance (EMDR)) where the EV mediated cross-talk is considered to play an important role [100,101]. The gene discussed is PGP; the disease is Miyoshi myopathy.