Comparative Antifibromatogenic Activity of Progesterone and Related Artificial Steroids^*†

This investigation has been aided by a grant from The Rockefeller Foundation, and from The Jane Coffin Childs Memorial Fund for Medical Research. Thanks are due also to Dr. Karl Miescher of Ciba Pharmaceutical Products in Basel, and to Drs. A. S. Cook of Ayerst, McKenna, and Harrison, of Montreal, for different steroids.

For clarity, we characterized steroids not occurring naturally as artificial, in distinction to steroids that are found in the body though used in a synthetic form.