FOXP3 and lung cancer: It has been demonstrated that the concentration of TGF-β in the plasma of NSCLC patients positively correlated with the frequency of circulating Treg cells and that TGF-β and Foxp3 were co-expressed in serial sections from tumor tissues of lung cancer (74), implying a contributing role of TGF-β in driving Treg generation in the process of NSCLC development.