Export receptor for importin alpha. Mediates importin-alpha re-export from the nucleus to the cytoplasm after import substrates have been released into the nucleoplasm (By similarity). Negatively regulates fluid secretion and plays a role in fluid homeostasis by down-regulating cftr activity (By similarity). Interacts with cftr. Shuttles between the nucleus and the cytoplasm. Belongs to the XPO2/CSE1 family.