Increased levels of IL-17, which contribute to an anti-cancer immune response, as well as CTLA-4 positive regulatory T cells, have also been highly associated with the bronchoalveolar lavage of the cancerous lung, suggesting that the anti-immune response was enhanced in the local cancerous microenvironment advocating for lung cancer progression and metastasis [14]. Here, CTLA4 is linked to lung carcinoma.