PAK1 and skin neoplasm: P21-activated kinases (PAKs) belong to the non-receptor serine/threonine protein kinase family, which play an important role in many signaling pathways, and thus contribute to cancer development.153 They can be classified into two groups, where group-I includes PAK1-3 and group-II includes PAK4-6.154 Abnormal expression of PAK1 is associated with skin cancer,155–157 breast cancer158 and pancreatic cancer.159