The function of SNX18 (sorting nexin 18, ENSG00000178996) is as follows. Involved in endocytosis and intracellular vesicle trafficking, both during interphase and at the end of mitosis (PubMed:18411244, PubMed:20427313, PubMed:21048941, PubMed:22718350). Required for efficient progress through mitosis and cytokinesis (PubMed:22718350). Required for normal formation of the cleavage furrow at the end of mitosis (PubMed:22718350). Plays a role in endocytosis via clathrin-coated pits, but also clathrin-independent, actin- dependent fluid-phase endocytosis (PubMed:20427313). Plays a role in macropinocytosis (PubMed:21048941). Binds to membranes enriched in phosphatidylinositol 4,5-bisphosphate and promotes membrane tubulation (PubMed:18411244). Stimulates the GTPase activity of DNM2 (PubMed:20427313). Promotes DNM2 location at the plasma membrane (PubMed:20427313). Together with DNM2, involved in autophagosome assembly by regulating trafficking from recycling endosomes of phospholipid scramblase ATG9A (PubMed:29437695). {ECO:0000269|PubMed:18411244, ECO:0000269|PubMed:20427313, ECO:0000269|PubMed:21048941, ECO:0000269|PubMed:22718350, ECO:0000269|PubMed:29437695}.