Avrum Bluming and Carol Tavris argue convincingly against estrogen as a causal factor in breast cancer. It is to note, however, that in our review of the published literature, we did notice a correlation between breast cancer and a phenotype where both estrogen and IGF-1 were elevated at the same time. Additional research in this area is needed. Simply dismissing estrogen involvement in postmenopausal breast cancer and being enthusiastic about hormone replacement are not the conclusions that we draw at our current understanding of the problem.