Acid sphingomyelinase deficiency (ASMD) is a progressive lysosomal storage disease caused by autosomal recessive pathogenic variants in the SMPD1 gene encoding acid sphingomyelinase (ASM). In a recent study, researchers from Albert Einstein College of Medicine aimed to assess the levels of plasma lyso-sphingomyelin, a deacylated form of sphingomyelin, in patients with ASMD pre- and post-treatment with olipudase alfa (recombinant-human acid sphingomyelinase).