Consistent with previous results, knockdown of HSPA9 inhibits cell growth and increased apoptosis of CD34+ cells cultured in erythroid media (Fig 1B and 1C).[10] To identify potential genes contributing to this phenotype, we flow sorted CD34+/CD71- cells from 4 independent cultures, 5 days after transduction with shLUC (control) and sh433 (shHSPA9 #2 in prior study).[10] sh433 was chosen to approximate haploinsufficient levels of HSPA9 mRNA observed in MDS samples with del(5q) compared to non-del(5q) samples.[4] We isolated CD34+/CD71- cells in order to study progenitor cells. The gene discussed is HSPA9; the disease is myelodysplastic syndrome.