Cancer antigens RAK-p120, p42, and p25, which exhibit biological, immunological and molecular similarity to the proteins expressed by Human Immunodeficiency Virus 1 (HIV-1), were found in 47 of 47 tested cases of serous adenocarcinoma of the ovary, and 45 of 45 tested cases of squamous carcinoma of the cervix. Normal ovary and cervix did not express antigens RAK. High molecular weight protein (RAK-p160) was detected in the blood of over 61% of ovarian and 72% of cervical cancer patients, and in 14.3% of healthy women with family history of breast and/or gynecological cancer. Antigens RAK might represent new diagnostic markers.