PAK1 and breast carcinoma: PAK1 is a member of PAK family of serine/threonine kinase, which is amplified in 33% of breast cancer, and has a critical roles in breast cancer.25 And also PAK1 serves as targets for the small GTP-binding proteins Cdc42 and Rac,26 which is involved in MAPK signaling pathway and actin remodeling.