The distribution of haptoglobin types in 526 cancerous and 430 noncancerous subjects is presented. The frequency of haptoglobin 1 gene, in females, ranged sequentially from 0.264 in patients with cancer of the cervix, uterus, and ovary, through melanoma, breast cancer, cancer of the colon, to 0.467 in reticuloses. This was supported by statistically significant differences observed between some groups of cancer patients and normal controls. A different haptoglobin 1 gene frequency was found for male cancer patients.