Seven cell lines, MOLM-6, -7, -8, -9, -10, -11 and -12, were established from a single blood sample from a patient with chronic myelogenous leukemia (CML) in blastic phase having the Ph1 chromosome abnormality. Based on immunophenotyping, two of these seven cell lines, MOLM-7 and -11, represented the megakaryoblastoid lineage, and the other five cell lines represented two different maturation stages of the myeloid lineage.