ADCs Toxins, Cryptophycins are potent microtubule inhibitors, with a mechanism of action similar to that of paclitaxel and vinca alkaloids. Treatment of cells with cryptophycins depletes microtubules through interaction with tubulin, thereby preventing cell division. Cryptophycins are capable of inducing apoptosis, possibly through other mechanisms in addition to that mediated by microtubule inhibition.