This gene encodes a protein that binds to the tumor suppressor folliculin and to AMP-activated protein kinase (AMPK), and may play a role cellular metabolism and nutrient sensing by regulating the AMPK-mechanistic target of rapamycin signaling pathway. The encoded protein may also be involved in regulating the O6-methylguanine-induced apoptosis signaling pathway. This gene has a closely related paralog that encodes a protein with similar binding activities. Both related proteins also associate with the molecular chaperone heat shock protein-90 (Hsp90) and negatively regulate its ATPase activity and facilitate its association with folliculin.