MYOM2 and pure red-cell aplasia: Additionally, a study showed co-culturing normal donor hematopoietic stem cells (HSCs) with serum from a PRCA patient containing M-protein led to a 43% reduction in colony-forming unit-erythroid lineage (CFU-E) and burst-forming unit-erythroid (BFU-E) compared to serum from a normal donor, suggesting inhibition of erythroid colonies by the monoclonal protein.