In 1973, Karmanos Cancer Institute researcher Herbert Soule, Ph.D. developed the MCF-7 human breast cancer cell line, which became the standard for human breast cancer research around the world.

The MCF-7 cell line at the Michigan Cancer Foundation (MCF, now named Barbara Ann Karmanos Cancer Institute, KCI) represents the first hormone responsive breast cancer cell line and was derived from the pleural effusion of a woman with metastatic breast cancer.

Establishment of the MCF-7 cell line led to the pivotal discovery of estrogen receptor (ER) and laid the path to future endocrine therapy research. The finding that estrogen stimulated MCF-7 cell growth whereas tamoxifen suppressed it, and that the tamoxifen suppressive effect could be reversed by estrogen, was “game changing” as it led to the concept of antiestrogens and the molecular cloning of ER. The MCF-7 cell line is used by researchers throughout the world as a model of ER positive breast cancer and for characterization of antiestrogen response and resistance.