This group also includes genes related to immunological functions, such as the SERPINA1 gene, which is involved in the complement pathway and in the coagulation cascade, cytokine, and interleukin signalling pathways, and the NOD-like receptor pathway (CXCL3), as well as others whose fundamental role is to protect against viral infections, as in the case of the BST2 gene. This evidence concerns the gene SERPINA1 and viral infectious disease.