The function of ENSG00000155256 (ZFYVE27, zinc finger FYVE-type containing 27) is as follows. Molecular tethering protein, which plays a role in the formation of membrane contact sites between the endoplasmic reticulum and late endosomes/lysosomes (PubMed:17082457, PubMed:25855459, PubMed:32686675). Promotes neurite formation by tethering endosomes to the endoplasmic reticulum membrane: interacts with Rab7-positive late endosomes, acting as a bridge to form endoplasmic reticulum membrane- endosome contact sites (PubMed:25855459, PubMed:32686675). Acts in cooperation with vesicle-associated membrane protein-associated protein (VAPA or VAPB), thereby facilitating loading of the endosome membrane with KIF5, which is required for movement of the endosomes along microtubules in the plus-end direction (PubMed:19289470, PubMed:21976701, PubMed:25855459). Also associates with Rab11-positive recycling endosomes, facilitating exocytosis and membrane expansion (PubMed:17082457). Contributes to both the formation and stabilization of the tubular endoplasmic reticulum network (PubMed:24668814). Involved in endoplasmic reticulum morphogenesis by regulating the sheet-to-tubule balance and possibly the density of tubule interconnections (PubMed:23969831). {ECO:0000269|PubMed:17082457, ECO:0000269|PubMed:19289470, ECO:0000269|PubMed:21976701, ECO:0000269|PubMed:23969831, ECO:0000269|PubMed:24668814, ECO:0000269|PubMed:25855459, ECO:0000269|PubMed:32686675}.