In this retrospective cohort study, we aimed to investigate the role of Fn in CRC by assessing (i) Fn prevalence and clinicopathologic associations, (ii) analyze transcriptional differences in MSS/pMMR rectal cancers, (iii) quantify spatial immune interactions via imaging mass cytometry (IMC), and (iv) evaluate Fn persistence in metastases. The gene discussed is FN1; the disease is rectal cancer.