. "Any process that stops, prevents, or reduces the frequency, rate or extent of microtubule polymerization." . . . . "negative regulation of microtubule polymerization" . "down regulation of microtubule polymerization" . "down-regulation of microtubule polymerization" . "downregulation of microtubule polymerization" . "inhibition of microtubule polymerization" . . .