SPP1 and infection: Such molecules include two elastase genes, Ela1 [67] and the neutrophil elastase Ela2 [68], known to play a role in peripheral tissues invaded by microbes [69], the Spp1 gene [70], and the secretory granule protein syncollin (Sync), expressed by neutrophils with a role in host defence to infections by invading bacteria, fungi, and protozoa [71].