Gy, 178: 102?M.-A. Jenabian et al.studied here, a strong positive correlation was observed between levels of plasma sCD40L and IDO enzyme activity when evaluated in all HIV-infected patients (Spearman's P = 0?05, r = 0?317, Fig. 2a). We and others have shown that higher IDO-induced Trp catabolism is involved in the imbalance of Th17/Treg in favour of Treg by stimulation of Treg differentiation in