KRAS and neoplasm: Overall, iCMS3 tumours were more likely to be associated with BRAF, KRAS, and PIK3CA mutations, whereas iCMS2 tumours were associated with mutations in APC and TP53. The authors propose a final model, termed the intrinsic-MSI-fibrosis (IMF) system, as the most informative as it considers the iCMS classification, microsatellite instability status, and levels of CAF-related fibrosis.