NFAR (nuclear factor associated with dsRNA) exists as two major protein species of 90 kDa (NFAR-1 or NF90) and 110 kDa (NFAR-2 or NF110) in the cell. NF90 and NF110 arise from a single gene named interleukin enhancer binding factor (ILF3) gene which resides on chromosome 19p13 and are generated through alternative splicing events. NF90 is a dsRNA binding protein that stabilizes mRNAs and regulates transcription. NF90 is a subunit of the nuclear factor of activated T-cells (NFAT) transcription factor that is required for T-cell expression of interleukin 2. The NF110 isoform is restricted to the nucleus and its function may be unrelated to NF90.