MDA-MB-231 cells were transfected with a control RNA duplex, or with one of two different TAP-1 RNA duplexes that reduce endogenous TAP-1 gene expression. A. After 48 hours, cells were transfected with Elk1-luciferase expression plasmids, and signaling activity was assessed after 48 hours. B. After 48 hours, cells were plated in soft agar, and the number of colonies was determined after 12 days. Error bars are standard deviations of three transfections conducted in parallel.