In this study, we combined an autochthonous colitis-associated CRC mouse model using STmΔaroA (an attenuated aromatic amino acid auxotrophic mutant) with the Nr4a3-Tocky-Ifng-YFP kinetic TCR-cytokine reporter, which has recently been utilised to detect favourable responses to ICB (Elliot et al, 2021). Here, IFNG is linked to colitis.