Epothilone F is a derivative or analogue of Epothilone D. Epothilone F is also an active metabolite of Epothilone D. In molecule of Epothilone F, a hydroxymethyl group is on the thiazole ring. Like taxanes, Epothilone F prevents cancer cells from dividing by interfering with tubulin. Early studies in cancer cell lines and in human cancer patients indicate superior efficacy to the taxanes. Epothilone's mechanism of action is similar to taxanes, but their chemical structure is simpler. Due to its better water solubility, cremophors (solubilizing agents used for paclitaxel which can affect cardiac function and cause severe hypersensitivity) are not needed.