According to the box plots in Figure 2D, it is more visually shown that plasma cells, CD8+ T cells, activated mast cells, Eos, and neutrophils increase to varying degrees, while B memory cells, T helper cells, CD4+ T memory cells, activated NK cells, and macrophages decrease significantly when samples from patients with COPD were compared with those from the normal population. This evidence concerns the gene CD4 and chronic obstructive pulmonary disease.