IGF1 and breast fibrocystic disease: For a typical woman in this study (that is, postmenopausal, 57 years old, BMI of 25, no family history of breast cancer, no personal history of benign breast disease, and so on), having two copies of IGF1-3D haplotype is associated with a mammographic density that is 5.9% lower than a woman with zero copies of the haplotype.