FAS and periventricular leukomalacia: However, BAY inhibited the cleavage of caspase-3 and mucosal apoptosis, and had no obvious effect on either Fas or FasL repression in PVL-treated p65ΔM/ΔM mice, although it did alleviate Fas and FasL expression in PVL-treated p65f/f mice (Fig. 7d).