Epothilones: A group of 16-member MACROLIDES which stabilize MICROTUBULES in a manner similar to PACLITAXEL. They were originally found in the myxobacterium Sorangium cellulosum, now renamed to Polyangium (MYXOCOCCALES).Tubulin Modulators: Agents that interact with TUBULIN to inhibit or promote polymerization of MICROTUBULES.Epoxy Compounds: Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.ThiazolesMyxococcales: An order of rod-shaped, gram-negative fruiting gliding bacteria found in SOIL; WATER; and HUMUS.Microtubules: Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.Tubulin: A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.Macrolides: A group of often glycosylated macrocyclic compounds formed by chain extension of multiple PROPIONATES cyclized into a large (typically 12, 14, or 16)-membered lactone. Macrolides belong to the POLYKETIDES class of natural products, and many members exhibit ANTIBIOTIC properties.Paclitaxel: A cyclodecane isolated from the bark of the Pacific yew tree, TAXUS BREVIFOLIA. It stabilizes MICROTUBULES in their polymerized form leading to cell death.Clinical Trials, Phase I as Topic: Works about studies performed to evaluate the safety of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques in healthy subjects and to determine the safe dosage range (if appropriate). These tests also are used to determine pharmacologic and pharmacokinetic properties (toxicity, metabolism, absorption, elimination, and preferred route of administration). They involve a small number of persons and usually last about 1 year. This concept includes phase I studies conducted both in the U.S. and in other countries.Clinical Trials, Phase II as Topic: Works about studies that are usually controlled to assess the effectiveness and dosage (if appropriate) of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques. These studies are performed on several hundred volunteers, including a limited number of patients with the target disease or disorder, and last about two years. This concept includes phase II studies conducted in both the U.S. and in other countries.Drug Resistance, Neoplasm: Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.Taxoids: A group of diterpenoid CYCLODECANES named for the taxanes that were discovered in the TAXUS tree. The action on MICROTUBULES has made some of them useful as ANTINEOPLASTIC AGENTS.Drug Resistance, Multiple: Simultaneous resistance to several structurally and functionally distinct drugs.