title: Carcinoma of the breast. Identical twins differing in time of onset and severity implicate non-genetic factors influencing clinical course.
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics*; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D014430:Twins, Monozygotic