Noticeable disparities were observed in various laboratory test indicators, including white blood cell (WBC) count, lymphocyte (LYM) count, neutrophil (NEU) count, C-reactive protein (CRP) levels, and lactic dehydrogenase (LDH) levels, as well as immunological markers (CD3, CD8, CD4, CD4/CD8 ratio), between non-PJP and PJP pediatric patients. This evidence concerns the gene CD4 and pneumocystosis.