Antigen presentation (B2m, Cd74, H2-D1, HLA-DMA, HLA-DRB, Psmb8, Tap2), embryonic development (C3, Celsr1, Erbb3, Impk, Mcl1), infectious disease (B2m, Ifngr1, Irf1, Myd88, Nr3c1), mast cell chemotaxis (C3, Cx3cl1), apoptosis of microglia (Btg1, Casp3, Cx3cl1, Myd88), tumorigenesis of polyp (Asph, Smad4), transport of prostaglandin E2 (Slco2a1), quantity of colonocytes (Guca2a), gastrointestinal disease (Asph, Cd84, Smad4). This evidence concerns the gene C3 and infectious disease.