Progressive infiltration of tumor-associated neutrophils (TANs) was observed during the evolution of benign papillomas to established SCC lesions in a chemical carcinogenesis model, and tumor escape mostly involved the impairment of anti-tumor CD8+ T cell responses mediated by high arginase activity, production of reactive oxygen species (ROS), nitrite (NO), and the induction of PD-1 expression on CD8+ T cells (Khou et al., 2020; Figure 1C). This evidence concerns the gene PDCD1 and neoplasm.