This study entails a thorough analysis of the genetic heterogeneity in colorectal peritoneal carcinomatosis, accompanied by comprehensive multi-region immuno-profiling to determine the expression of SATB2, a sensitive and highly specific marker for colorectal cancer, RBM3, a candidate prognostic and predictive biomarker, as well as a standard panel of mismatch repair proteins. Here, RBM3 is linked to colorectal cancer.