In addition, our results suggested that only class II PI3Ks were involved in MM cell migration toward CXCL12, since only the addition of 1 μM WM (which inhibits all classes of PI3K) but not 100 nM WM (which selectively inhibits Class I PI3K) impaired CXCL12-induced MM cell migration. This evidence concerns the gene CXCL12 and Miyoshi myopathy.