Furthermore, lung cancer markers including Kras, c-Myc, ABCG2, OCT4, SOX2 and Aldh1a1 induced by PM2.5 were also markedly abolished when IL-17a was knocked out; however, p53 and PTEN mRNA expression levels restrained by PM2.5 were significantly rescued in mice with the loss of IL-17a (Figure 8H). Here, IL17A is linked to lung cancer.