NEU1 and galactosialidosis: However, a large number of studies, based on fibroblasts derived from patients with congenital sialidosis or galactosialidosis, NEU1-deficient mice, mice devoid of NEU1 activity in their hematopoietic lineage, or cells transfected with either NEU1 siRNA or a catalytically inactive NEU1 mutant, has definitely proved that NEU1 is the only membrane sialidase that is part of the ERC and which  plays pivotal role in ERC-mediated signal transduction and biological effects [13, 25, 27, 38].