. "Any process that decreases the rate, frequency, or extent of protein tyrosine kinase activity." . . . . "negative regulation of protein tyrosine kinase activity" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .