Cholesterol-binding protein involved in the redistribution of cholesterol from lipid droplets to the endoplasmic reticulum (PubMed:32358067). Required to meet cholesterol demands during erythropoietic differentiation (PubMed:32358067). 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 (By similarity). Homotetramer. May also form homodimer. Localizes to the plasma membrane and intracellular membranes in developing and mature erythrocytes. Expressed in erythrocytes (at protein level). The C-terminal region mediates cholesterol-binding. Defects in TSPO2 functioning alter the cation composition of canine erythrocytes so that they are high in potassium and low in sodium (HK phenotype) (PubMed:32358067). Although HK erythrocytes have a tendency to hemolyze they do not cause serious disease, but the phenotype may lead to misdiagnosis of hyperkalemia in HK canines and blood transfusions using HK blood may induce hyperkalemia (PubMed:32358067). This phenotype has been identified in the Shiba breed (PubMed:32358067). Belongs to the TspO/BZRP family.