CEACAM5 and colon carcinoma: Indeed, when 12 identical Pcs were conjugated to a 35A7 Mab directed against CEA (35A7 Mab-(AlPcS4A1)12), a tumor-to-muscle ratio and tumor-to-skin ratio of 33 and 8, respectively, was reported in nude mice bearing a human colon carcinoma xenograft [92].