There is another interesting point regarding the degree of lung injury associated with PJP and our patient's low CD8+ T cells on presentation that increased only after hospital discharge. In vitro data by Gigliotti et al. [28] indicate that although CD8+ T cells may not play a significant role in control of P. jiroveci replication they consist a key component of the inflammatory response and consequent lung injury induced by the organism. The gene discussed is CD8A; the disease is pneumocystosis.