Vitamin D treatments upregulated inducible nitric oxide synthase (NOS2A) and β-defensin (i.e., DEFB7) in bovine monocytes (Merriman et al., 2015) and reduced Staphylococcus aureus infection of bovine mammary epithelial cells (Yue et al., 2017). The gene discussed is NOS2; the disease is staphylococcus aureus infection.