The function of NEU3 (neuraminidase 3, Ensembl gene identifier ENSG00000162139) is as follows. Exo-alpha-sialidase that catalyzes the hydrolytic cleavage of the terminal sialic acid (N-acetylneuraminic acid, Neu5Ac) of a glycan moiety in the catabolism of glycolipids, glycoproteins and oligosaccharides. Displays high catalytic efficiency for gangliosides including alpha-(2->3)-sialylated GD1a and GM3 and alpha-(2->8)- sialylated GD3 (PubMed:10405317, PubMed:10861246, PubMed:11298736, PubMed:12011038, PubMed:15847605, PubMed:20511247, PubMed:28646141). Plays a role in the regulation of transmembrane signaling through the modulation of ganglioside content of the lipid bilayer and by direct interaction with signaling receptors, such as EGFR (PubMed:17334392, PubMed:25922362). Desialylates EGFR and activates downstream signaling in proliferating cells (PubMed:25922362). Contributes to clathrin- mediated endocytosis by regulating sorting of endocytosed receptors to early and recycling endosomes (PubMed:26251452). {ECO:0000269|PubMed:10405317, ECO:0000269|PubMed:10861246, ECO:0000269|PubMed:11298736, ECO:0000269|PubMed:12011038, ECO:0000269|PubMed:15847605, ECO:0000269|PubMed:17334392, ECO:0000269|PubMed:20511247, ECO:0000269|PubMed:25922362, ECO:0000269|PubMed:26251452, ECO:0000269|PubMed:28646141}.