The goal of the study was to assess the different immunohistomorphologic characters in adenomas and adenocarcinomas using the Ki-67 tumor proliferation marker that may have diagnostic or prognostic relevance.  Materials and methods: This descriptive study was conducted on 40 paraffin-embedded tissue blocks collected from the colorectal tissues in a tertiary care hospital in Chennai, Southern India. The gene discussed is MKI67; the disease is adenocarcinoma.