CA2 and viral infectious disease: Genes in this signature code for proteins that are viral infection restricting factors (e.g. Ifitm1, Ifitm3, Gbp7), that protect against cellular or environmental stress (e.g. Abcb1a, Car2, Ern1, Serpina3g) or that regulate immune activation processes (e.g. Fgl2, Anxa1, Havcr2).