CBFβ-SMMHC did not increase the clonogenic survival of Ba/F3 cells. MTCB6 or MTINV-3 cells were cultured ± zinc for 18 hours. VP-16 was then added to 0.04 μg/mL to an aliquot of each cell line. Culture was then continued in the same conditions in two 96-well dishes per group. Cells were plated at 0.3 to 2 cells/mL, based on the results of preliminary experiments, so that between 10% and 50% of the wells would develop a colony. The number of colonies were scored 8 days later, and the proportion of initially plated cells that formed colonies is shown for each cell line and culture condition.