We suggest that such a substance may be the epidermal growth factor (EGF), whose synthesis and function is under the control of androgens [36] and whose receptor (EGFR or HER1) is expressed in 13-44% of breast cancers [37-41] and in 6% of cases in a study by Barghava et al. [42], who used more stringent criteria in defining EGFR overexpression. Here, EGFR is linked to breast cancer.