In colon and rectal cancer appropriate for resection (non-metastatic), chest, abdominal, pelvic computed tomography (CT), pelvic magnetic resonance imagining (MRI), complete blood count, chemistry profile and CEA, enterostomal therapist as indicated for the preoperative marking of the site [125] and in rectal cancer proctoscopy endorectal ultrasound (if MRI is contraindicated or for superficial lesions) have to be considered [99]. The gene discussed is CEACAM5; the disease is rectal cancer.