Expression of transgenic Vav3 rescues Vav3-deficient, p190-BCR-ABL⁺ leukemogenic cell survival. (A) Representative example (n = 4) of pVav3 and Vav3 expression in WT or Vav3^−/− p190-BCR-ABL⁺ B-cell progenitors transduced with either empty vector (WT; Mock or Vav3^−/−; Mock) or Vav3 (WT;Vav3 or Vav3^−/−;Vav3). The level of Vav3 phosphorylation (pVav3/Vav3 density ratio) is presented normalized to the WT;Mock value. (B) Apoptosis as determined by annexin V binding of transduced B-cell progenitors (day 15 of culture). **P < .005; ***P < .001. Each experiment was done in triplicate and data are represented as means ± SD. (C) Representative example of FACS analysis of annexin V binding.