FOXO3 and chronic myelogenous leukemia, BCR-ABL1 positive: To our surprise, enforced treatment in vitro with PGE2 restored this interaction within the nuclei of Lgr4/Gpr48-hypomorphic mutant LT-CML stem cells, but not in Gdpd3-deficient LT-CML stem cells (where Foxo3a was inactivated in the cytoplasm).