CD4 and lung cancer: As shown in Fig. 5b–g, the infiltration of most immune cell types was higher in primary lung cancers than metastases with the exception of macrophages, which were higher in metastases (Fig. 5d) and CD4+ T cells that were similar between primary and metastases (Fig. 5f), which led to higher CD4/CD8 ratio in metastases, although the difference did not reach statistical significance (Fig. 5h).