PAK2 and gastric cancer: PAK2 is the sole universally expressed member of the serine/threonine kinase P21‐activated kinase family,[18] and its elevated expression is associated with advanced clinical stages of ovarian and pancreatic cancers.[88, 89] In addition, PAK2 has been proposed as an independent prognostic marker for gastric cancer.[90] The expression of PAK2 in tumor cells is regulated by various endogenous upstream regulators.