CTLA4 and squamous cell carcinoma: We observed a statistical difference in the distribution of cytotoxic T cells CD8+ and TILs CTLA-4+ between adenocarcinomas and large cell carcinomas (P = 0.034 and P = 0.024, respectively), whereas the distribution of macrophages CD68+ differed both between adenocarcinomas and large cell carcinomas (P = 0.007) and adenocarcinomas and squamous cell carcinoma (P = 0.005).