CD38 and Miyoshi myopathy: In a next step, the most potent drugs (17AAG, BI2536, BEZ235) were examined for their effects on survival of primary BM-derived plasma cells, putative neoplastic MM stem cells, CD34+/CD38− hematopoietic stem cells (HSC) and CD34+/CD38+ hematopoietic progenitor cells by staining for active caspase-3 and Annexin V/DAPI.