CMI abolished tumour-induced DLB and cognitive impairment; ↓ tumour-induced NI (↓NFκB, IL-1β, TNF-α, IL-10, IDO, and COX-2) and OS (altered expression of iNOS and Nrf2, ROS, NO, lipid peroxidation, and SOD activity) in mouse PFC and Hippoc. Here, IDO1 is linked to Cognitive impairment.