FOXP3 and cancer: The number of effector T cells in LS-SCLC was significantly more than that in ES-SCLC, and the high ratio of effector T cells to Treg cells predicted a long-term survival.71 FOXP3 is a specific biomarker of Treg cells, and its role in cancers is conflicting.72 Especially for SCLC, FOXP3+TILs presented inconsistent associations with prognosis.