The lung adenocarcinoma samples examined by ex vivo analysis after Romanovsky–Giemsa staining had a higher number of immune cells than most lung squamous cell carcinoma samples did (Table 2, Figure 4 and Figure 5), especially immune cells from the myeloid lineage, where macrophages in tumor samples ad1 and ad4-ad8, neutrophils in tumor sample ad2, and eosinophils in tumor sample ad3 were the dominant immune cell populations. This evidence concerns the gene PSEN2 and lung adenocarcinoma.