FOXP3 and immune system disorder: Forkhead box P (FOXP) TFs—FOXP1, FOXP2, FOXP3, and FOXP4—are involved in embryonic development, immune disorders, and cancer progression, but FOXP3’s targeting of CD4 + CD25+ regulatory T (Treg) cells and its dual role as an OCG or tumor suppressor in cancers are unclear and controversial.169