. "\"Any process that activates or increases the frequency, rate or extent of axon extension.\" [GOC:go_curators]" . . "positive regulation of axon extension" . "up regulation of axon extension" . "up-regulation of axon extension" . "upregulation of axon extension" . . . . . "activation of axon extension" . "stimulation of axon extension" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .