Moreover, α1PI is a primary regulator of the function of mature CD4+ T cells by directly halting their migration within pathological tissue sites such as in bacterial infection, virus infection, host-derived inflammation, and tumors where α1PI becomes inactivated by extraneous proteinases thereby preventing cellular locomotion and transforming α1PI into a neutrophil chemoattractant, a situation creating poor cancer prognosis (15, 17, 26, 27). This evidence concerns the gene CD4 and cancer.