Eide PW, et al. - In colorectal cancer (CRC), elevated miR-31 expression is related to poor outcome, so researchers investigated if prognostic information is independent of known molecular subgroups and gene expression-based consensus molecular subtypes (CMS). For this purpose, they examined around 2,000 CRC biopsies and preclinical models. The expression of miR-31-5p and its host transcript long noncoding RNA MIR31HG was strongly correlated. In 158 out of 1,265 (12%) of pCRCs (primary colorectal cancers), MIR31HG outlier expression was found, which was related to depletion of CMS2-canonical subgroup and shorter relapse-free survival (RFS) in multivariable analysis. MIR31HG outlier status had a prognostic ability independent of cytotoxic T lymphocyte and fibroblast infiltration. Findings revealed that clinical stratification outside of major gene expression phenotypes and tumor immune and stromal cell infiltration was enabled by MIR31HG expression.