Effect of p160 depletion on apoptosis of MCF-7 cells. MCF-7 cells were plated in media containing 10% FBS and 24 h later were transfected with siRNA targeting luciferase as a negative control (siCont), SRC-1 (siSRC-1), SRC-2 (siSRC-2), or SRC-3 (siSRC-3). After transfection, media were replaced with phenol-red-free DMEM and 2.5% sFBS for 48 h, and cells were exposed to VEH (0.1% ethanol) for an additional 24 h. Apoptosis was detected in cells using a cell death ELISA, and the data represent the mean OD ± sem of nine experiments. Statistical analyses were by one-way ANOVA: *, P < 0.05; or **, P < 0.01 vs. control siRNA-transfected cells.