Studies identified associations with coinfections, such as Neospora caninum, bovine herpesvirus type 1 (BoHV-1), mastitis, Leptospira spp., bovine leukemia virus (BLV), and parainfluenza virus 3 (PI-3), and with symptoms such as abortion, fever, reproductive problems, and mortality. The gene discussed is PI3; the disease is mastitis.