. "Any process that stops, prevents, or reduces the frequency, rate or extent of S phase of mitotic cell cycle activity." . . . . "negative regulation of S phase of mitotic cell cycle" . "down regulation of S phase of mitotic cell cycle" . "down-regulation of S phase of mitotic cell cycle" . "downregulation of S phase of mitotic cell cycle" . "inhibition of S phase of mitotic cell cycle" . "negative regulation of S-phase of mitotic cell cycle" . . .