This limitation to GALC overexpression coupled to moderate enzyme secretion by transduced cells and/or insufficient uptake by GLD cells (cross-correction) suggested by previous studies (Ricca et al., 2015; Weinstock et al., 2020) may explain the partial effect of conventional HSCT and the little advantage of HSC-GT in GLD mice (Galbiati et al., 2009; Gentner et al., 2010; Rafi et al., 2015a). The gene discussed is GALC; the disease is Krabbe disease.