P2RX7 and pneumocystosis: Next, we have attempted to replicate findings obtained with P2rx7 gene deficient mice by systemic treatment with the selective, brain permeable P2X7 receptor antagonist JNJ-47965567 (Bhattacharya et al. 10), which was administered as a single i.p. treatment at a 30 mg/kg dose 30 min prior to PCP regimen (Fig. 2a).