PI3 and neoplasm: IL5 is involved in the regulation and recruiting of eosinophils, which are critical for the suppression of tumor metastasis [82, 83], while an upregulation of PI3 counterbalances the mitogenic effects of the PI3 substrate elastase from activated neutrophils in the tumor microenvironment, thus reducing proliferation, tumorigenesis and migration [84, 85] as well as increasing apoptosis in tumor cells [86].