Other potential reasons for Quin stockpiling include the fact that many bacteria secrete NAD+ glycohydrolases [e.g., tuberculosis necrotizing toxin or TNT, streptococcus pyogenes beta-NAD+(+) glycohydrolase, known as SPN, etc.] that deplete intracellular NAD+ levels in macrophages, leading to cell death (108–110). Here, SPN is linked to tuberculosis.