Background
MSI-H CRC comprises ~15% of CRC & has higher PD-1 & PD-L1 (P(+)) expression in CD4+ lymphocytes & tumor cells, respectively, compared to non-MSI-H CRC. Immune-checkpoint inhibitor therapy is being tested in clinical trials for MSI-H CRC (NCT02060188, NCT01876511). Human homologue of Groucho, Transducin-like-Enhancer of Split orthologue (TLE-3), inhibits Wnt signaling by competition with b-catenin for LEF/TCF binding. We investigated different biomarkers that may characterize P(+) MSI-H CRC.