Bcl-2 expression in WAS lymphocytes is attenuated as compared with Bcl-2 expression in normal lymphocytes. MFI of the Bcl-2 signal was measured either immediately after isolation or after in vitro incubation for 24 or 48 hours. Samples from 5 different WAS patients and 7 different normal controls were analyzed. An unbalanced repeated measures ANOVA showed that the differences in Bcl-2 expression levels between the 2 groups, normal and WAS, at each time point (0, 24, and 48 hours) are significant (P = .0233, .00985, and .0192, respectively).