In addition, the proportion of Treg cells was changed by sh-TBX21-transfected PCa cells, not by directly silencing TBX21 in CD4+ T cells, implying that PCa cells might induce the immunosuppressive microenvironment by TBX21, possibly via directly interacted with receptors in CD4+ T cells or release vesicles supplemented with TBX21. The gene discussed is CD4; the disease is posterior cortical atrophy.