CD4 and idiopathic pulmonary fibrosis: Based on the box plots, memory CD4+ T cell, M1 macrophage, M2 macrophage, dendritic cell, neutrophil, and naive B cell populations were significantly decreased, whereas naive T cell, monocyte, and mast cell populations were significantly increased, indicating that IPF development might be related to immune cell type imbalances (Figure 3B).