Importantly, strong negative correlations were detected between the numbers of neutrophils and those of CD4+CD8+ cells in the TMEs of both subtypes of NSCLC, but not in non-adjacent lung tissue, while PD-1-expressing CD4+ T cells correlated with tumor size and clinical stage (Kargl et al., 2017). The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.