To study the direct effect of MM-derived Jagged on tumor angiogenesis, we interfered with the Jagged1 and Jagged2 expression in two MM cell lines, RPMI8226 and OPM2, and demonstrated that their silencing was associated with a reduced ability of MM cells to induce HPAEC organization in tube-like structures. The gene discussed is JAG2; the disease is Miyoshi myopathy.