Forty‐eight patients with carcinoma of the breast and 122 controls from the Boston area were typed for 24 HL–A specificities. Types were assigned objectively by a computer program, and two controls were matched to each of 40 breast cancer patients on the basis of the countries of origin of the patients’ ancestors or race. Our data fail to confirm an association of HL–A7 with breast cancer suggested by the data of Patel and coworkers (1972) who typed 52 patients from the Boston area. In the present study, no HL–A specificity or pairs of specificities were found to be significantly more or less frequent in breast cancer patients than in