. "\"Any process that activates or increases the frequency, rate or extent of smooth muscle cell differentiation.\" [CL:0000192, GOC:ai]" . . "positive regulation of smooth muscle cell differentiation" . "up regulation of smooth muscle cell differentiation" . "up-regulation of smooth muscle cell differentiation" . "upregulation of smooth muscle cell differentiation" . . . "activation of smooth muscle cell differentiation" . "stimulation of smooth muscle cell differentiation" .