A clinical study to evaluate the Makari Intradermal Test (MIT) involved 180 patients seen with symptoms suggestive of malignant disease, 85 of whom were subsequently shown to have carcinoma of the large bowel, and 66 asymptomatic volunteers. The prognostic value of initial and serial studies relative to patient-survival rate and the efficacy of serial studies in detecting disease in long-term follow-up of patients with resected malignant lesions were evaluated. On the basis of this study, the MIT appears to merit further investigation, not as a definitive diagnostic procedure, but as a survey for identifying patients with early malignancy or individuals at high risk to malignant epigenesis.