PCP positive cases showed 7.86 fold IL-2, 5.15 fold IL-10, 5.89 fold IL-4, 8.77 fold IL-13 mRNA expression, while negative cases showed 4.38 fold IL-2, 2.89 fold IL-10, 3.36 fold IL-4, 6.84 fold IL-13 mRNA expression and differences among them was found to be significant (p< 0.0001, p< 0.0001, p< 0.0001, p=0.04), respectively. Here, IL4 is linked to pneumocystosis.