FOXP3 and non-small cell lung carcinoma: Prognostically, the relative accumulation of Tregs in NSCLC tumors, and peripheral blood of SCLC patients (in relation to effector T cell populations) has been linked to increased risk of recurrence, and a high proportion of FoxP3+ lymphocytes in SCLC lung tumor biopsies correlates with poor survival [67, 68, 74, 75].