B. DRUGS The Vinca alkaloids vinblastine (VLB) and vindesine (VDS), documented MTI known Tubulozole, a synthetic MTI, I3 exists in two isomeric forms: one active, tubulozole-cis (T-C), and one inactive, tubulozole-trans (T-T), on microtubules. T-T has no antiturnor activity. Therefore, tubulozole is a most appropriate compound to use to analyze MTIspecific effects. T-C has been shown to be effective on MO, cellsI4 and on 3LL cells.