RAC1 and breast cancer: The co‐immunoprecipitation assays showed that TNFAIP2 interacts with actin and is involved in the formation of actin‐based membrane protrusions in NPC‐TW02 cells.4, 9 We reported that TNFAIP2 interacts with the 2 small GTPases, Rac1 and Cdc42, thereby regulating actin cytoskeleton and cell morphology in breast cancer cells.