CPD and infection: Other genes up-regulated in both in vivo conditions in VNI include: APP1 that encodes a secreted extracellular antiphagocytic protein, which inhibits the attachment and ingestion of yeast cells by alveolar macrophages; CXD3, a carboxypeptidase D correlated with capsule size [38]; and SRX1, a sulfiredoxin required for cells to counteract peroxide stress and virulence of C. neoformans in mouse infection models [39].