Tubulysin D is a highly cytotoxic anti-microtubule toxin (anti-microtubule toxins) that is synthesized as an ADC cytotoxin (ADC Cytotoxin) . Tubulysin D can be isolated from the myxobacteria Archangium geophyra and Angiococcus disciformis. Tubulysin D displays extremely potent cytotoxic activity in mammalian cells, including multidrug-resistant cell lines, with IC50 values in the low nanomolar range. Tubulysin D inhibits microtubule/Tubulin polymerization and leads to cell cycle arrest and apoptosis[1][2].