GAL3ST1 and metachromatic leukodystrophy: In MLD, the therapeutic focus in substrate reduction therapy is the development of a specific, potent, and competitive inhibitor which targets the catalytic action of the rate-limiting enzyme, cerebroside sulfotransferase, that is involved in the biosynthesis of sulfatides (Singh and Singh, 2024b; Yaghootfam et al., 2007; Li et al., 2020).