CBFβ-SMMHC does not slow the rate of cell death resulting from IL-3 withdrawal in Ba/F3 cells. MTINV-3 cells were cultured ± zinc chloride for 18 hours. They were then washed three times with PBS and cultured without IL-3. Cells initially exposed to zinc were continued in zinc. At 0, 6, 18, 24, and 42 hours an aliquot of cells from each culture was analyzed for the proportion of surviving cells by PI staining and FACScan analysis. Mean results from duplicate experiments are shown. Standard errors (SEs) were smaller than the data points depicted.