IDO1 and coronary stenosis: Significant correlation was found between degree of IDO activity and the degree of RCA stenosis, but not for other anatomical distribution of coronary arterial stenosis (rs = 0.169, p = 0.003 for RCA; rs = 0.062, p = 0.284, for LAD; and, rs = 0.093, p = 0.106 for LCX).