Background：

The protein encoded by this gene is a cytokine that is specifically induced by apoptosis， and it is involved in the control of angiogenesis， inflammation， and wound healing. The release of this cytokine renders the tumor-associated vasculature sensitive to tumor necrosis factor. The precursor protein is identical to the p43 subunit， which is associated with the multi-tRNA synthetase complex， and it modulates aminoacylation activity of tRNA synthetase in normal cells. This protein is also involved in the stimulation of inflammatory responses after proteolytic cleavage in tumor cells. Multiple transcript variants encoding different isoforms have been found for this gene. A pseudogene has been identified on chromosome 20.