. "Any process that activates or increases the frequency, rate or extent of the introduction of a phosphate group to a tyrosine residue of a Stat1 protein." . . . "positive regulation of tyrosine phosphorylation of Stat1 protein" . "activation of tyrosine phosphorylation of Stat1 protein" . "stimulation of tyrosine phosphorylation of Stat1 protein" . "up regulation of tyrosine phosphorylation of Stat1 protein" . "up-regulation of tyrosine phosphorylation of Stat1 protein" . "upregulation of tyrosine phosphorylation of Stat1 protein" . . .