Clinical and molecular characteristics of XPO1 mutations in patients with chronic lymphocytic leukemia.

The (exportin) gene (also referred to as chromosome region maintenance 1; ) is a karyopherin that exports proteins and RNA fragments from the nucleus into the cytoplasm., The human gene, located on chromosome 2 (2p15), is believed to encode an oncogenic protein since many of the molecules exported by into the cytoplasm are associated with either known tumor-suppressor genes, such as or , or transcription factors that contribute to cell proliferation and survival such as IkB-α or whose accumulation in the nucleus results in cell death. The binding of to various proteins is mediated by recognizing the leucine-rich nuclear export signals (LR-NES) on the N-terminus of snurportin 1 (SNUPN) forming a nuclear pore complex or a cargo, thereby transporting proteins out of the nuclear membrane. Overexpression, deregulation, or dysfunction of has been reported in various types of cancer. is a therapeutic target in CLL, and selective inhibitors of nuclear transport (SINE) such as selinexor are now being investigated in clinical trials in CLL.