Taxol is a member of the antineoplastic (anticancer) class of chemicals that is used to combat the proliferation of cancer. The primary focus of Taxol is treatment of ovarian cancer when other avenues of chemotherapy have failed. Taxol was originally isolated from the bark of the Pacific Yew tree, and it's use led to a controversy over the destruction of these endangered trees to produce the drug (it takes the death of four trees to produce enough taxol for a single human dose). Subsequently, a synthetic pathway, utilizing the needles of the more common English Yew, was discovered by Dr. Robert Holton of the Florida State University, and we all lived happily ever after.