We also observed that the overexpression of RUNX1-R135T in K562 cells, a heterozygous ASXL1 mutant CML cell line, augmented cell growth and impaired PMA-induced megakaryocytic differentiation as evidenced by the reduction of CD61 expression with immature cell morphology in RUNX1-R135T-expressing K562 cells. The gene discussed is ASXL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.