Exogenous riboflavin directly controls infection in three ways: 1) it inhibits transcription of bacterial LPS (Figure 2b); 2) it reduces the level of NO or expression of iNOS; and 3) it regulates the functions of innate immune cells (such as macrophages and neutrophils) and the levels of immunoreactive materials, including TNF, ILs, and IFN. This evidence concerns the gene IFNA1 and infection.