May act as a guanine nucleotide exchange factor (GEF). Concentrated in the perinuclear region. Ubiquitously expressed but enriched in brain. In brain, it is expressed at higher level in olfactory bulb and cerebellum and peaks perinatally (from 16 dpc to P0.5). May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Truncated N-terminus. Extended N-terminus. Probable cloning artifact. Intron retention.