In a study on the impact of plasma xanthine oxidoreductase (XOR) activity, which is linked to ROS production, women had a lower plasma XOR activity cut-off value for predicting the occurrence of coronary artery spasm than that had by men.34 Despite this assumption, the differences in the effect of uric acid between sexes remains unclear, highlighting the need for further studies to better understand these differences. Here, XDH is linked to coronary vasospasm.