CD4 and bronchopulmonary dysplasia: As shown in Supplementary Figure S6A, the proportions of M0 macrophages and neutrophils were elevated in the BPD samples compared to the control samples (p < 0.001), whereas, the proportions of CD8T cells, CD4 naive T cells, CD4 resting memory T cells, and M2 macrophages were elevated in the control samples compared to the BPD samples (p < 0.001).