We further examined the extent to which NAD+ production contributes to the protective effects of 3‐HAA on PCOS by treating 3‐HAA‐administered mice with phthalic acid (PA), an inhibitor of quinolinate phosphoribosyltransferase (QPRT), the rate‐limiting enzyme in de novo NAD+ biosynthesis[35] (Figure 5A). This evidence concerns the gene QPRT and polycystic ovary syndrome.