To assess the involvement of MM cell-derived Jagged ligands in angiogenesis promotion, we knocked down (KD) the ligands in two human myeloma cell lines (HMCLs), namely RPMI8226 and OPM2, by using siRNAs targeting Jagged1 or Jagged2 (HMCLsKD) or the corresponding scrambled siRNA as the control (HMCLsSCR), as previously reported [6,10]. Here, JAG1 is linked to plasma cell myeloma.