Cholesterol-binding protein involved in the redistribution of cholesterol from lipid droplets to the endoplasmic reticulum (PubMed:19729679). Required to meet cholesterol demands during erythropoietic differentiation (PubMed:19729679). May play a role in transport processes at the plasma membrane of erythrocytes, including regulating VDAC-mediated ATP export, and import of the heme precursors protoporphyrin IX and 5-aminolevulinic acid (PubMed:27641616, PubMed:30061676, PubMed:31989647). Homotetramer (PubMed:27641616). May also form homodimer (PubMed:27641616). Localizes to the plasma membrane and intracellular membranes in developing and mature erythrocytes. Expressed in erythrocytes (at protein level). Expression levels increase during erythrocyte differentiation. The C-terminal region mediates cholesterol-binding. Belongs to the TspO/BZRP family.