MRC1 and mismatch repair cancer syndrome 1: In an attempt to find an association between MMR deficiency and immune infiltration, Touat et al., 2020 found that while there was a high T-cell infiltration in CRC patients with MMR deficiency, as compared to their MMR-proficient counterparts, both MMR-proficient and post-treatment MMR–deficient glioma patients had reduced T-cell infiltration.