Importantly, as well as driving MM cell survival, IGF-1 has also been shown to mediate drug resistance, including to dexamethasone, which could be reversed when cells were treated with either the PI3K inhibitor LY294002 or the mTOR inhibitor rapamycin, but not with the MAPK inhibitor PD98059 [48]. This evidence concerns the gene IGF1 and Miyoshi myopathy.