CBS and homocystinuria: In the present study, we confirm that female Cgl null mice exhibit severely elevated tHcy which is some three-fold greater than that observed in male Cgl null mice and at a level indistinguishable from those observed in both sexes of a Cbs null mouse model of classical homocystinuria (HCU) that incurs severe liver damage (Maclean et al., 2010a).