DESeq2 analysis with adjustment for nine covariates (GA, BW, sex, cell-type % of CD4 + T, CD8 + T, B cell, NK, granulocyte, and monocyte) determined DEGs (731 genes at p < 0.01) in peripheral blood RNA of BPD samples on day 14 (Table 4; Additional file 1: Table S6). Here, CD8A is linked to bronchopulmonary dysplasia.