IL10 and cancer: In particular, we found that urban collected PM (i.e., PM10 and PM1) and the sub-micrometric component, Soot, lead toward lung inflammation characterized by the recruitment of immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs) and M2 macrophages, which were Arginase I positive, and that were correlated to the presence of both anti-inflammatory cytokines (i.e., IL-10) and suppressive Treg, paving the way for some respiratory disorders (i.e., cancer).