GALC and Krabbe disease: The moderate benefit of HSC-GT in GLD mice might depend on the poor GALC overexpression achieved in HSPCs and progeny, possibly coupled to modest enzyme secretion and/or insufficient uptake by GLD cells (cross-correction), particularly in the CNS (Gentner et al., 2010; Ungari et al., 2015; Weinstock et al., 2020).