Interacts with FMR1, FXR1 AND FXR2. Component of the WAVE1 complex composed of ABI2, CYFIP2, BRK1, NCKAP1 and WASF1/WAVE1. CYFIP2 binds to activated RAC1 which causes the complex to dissociate, releasing activated WASF1. The complex can also be activated by NCK1.