The BALF ratios of TNF-α/IL-10, IL-8/IL-10, IL-1β/IL-10, TNF-α/TGF-β1, IL-8/TGF-β1, IL-1β/TGF-β1 and IL-1β/IL-1RA were significantly higher in mixed than in pure PJP patients. This evidence concerns the gene TGFB1 and pneumocystosis.