The limitation of this study is that, due to insufficient biological material, we were unable to isolate the distinct Treg subtypes in order to evaluate their suppressive function in vitro. Despite this fact, we performed co-culture experiments using an enriched isolated Treg population (CD4+CD25+CD127−/dim) from both NSCLC patients and HDs and proved that this enriched population had suppressive capacity, since they could reduce the production of IFNγ by activated CD4+ T cells (Fig. 3F). Here, CD4 is linked to non-small cell lung carcinoma.