CEACAM5 and colonic neoplasm: Furthermore, rats with N-methylnitrosourea (NMN)-induced colon cancer fed RE, showed significant alterations in cell death modulating proteins including cytochrome c, programmed cell death protein 4 (PCDP4), carcinoembryonic antigen (CEA) and colon-cancer specific antigen-4 (CCSA-4) [43].