As for patients with metastatic SCLC, a similar insignificant association with survival was observed in another study that performed FOXP3+TILs IHC staining on brain metastasis specimens of patients with SCLC.65 Wang et al74 included 65 SCLC patients without stage information and demonstrated patients with a higher ratio of FOXP3/CD45 cells (measured as Tregs) had a worse median OS (120 vs 410 days). Here, FOXP3 is linked to small cell lung carcinoma.