BMP2 and chronic myelogenous leukemia, BCR-ABL1 positive: Of note, studies from the Zon laboratory showed BMP2 treatment of K562 and U937 recruited phosphor SMAD1 with lineage specific factors (erythroid factor GATA1 in K562 cells derived from chronic myelogenous leukemia in erythroid blast crisis and CEBPA in U937 myelomonocytic cells) [71].