32D-neo (□), 32D-c-myc (◊), and 32D-max (○) cells were treated as described in Fig 1 except that they were also maintained in IL-3–depleted medium for the duration of the experiment. Viability was then determined at 18 hours for ADR, CPT, VP-16, and CDDP; 14 hours for N-Mus; and 16 hours for Taxol. The results shown here are the average of three experiments ±1 SE. Note that the viability of the cells in the absence of drug is not 100% due to cell death caused by the absence of IL-3. Viability was again scored by trypan blue exclusion. Apoptotic DNAs are again depicted as in Fig 1.