Tryptophanyl-tRNA synthetase (WRS) basically catalyzes the ligation of tryptophan with tryptophanyl-tRNA. WRS is overexpressed by IFNg and secreted to inhibit the vascular angiogenesis. Two forms of tryptophanyl-tRNA synthetase exist, a cytoplasmic form, named WARS, and a mitochondrial form, named WARS2. Tryptophanyl-tRNA synthetase (WARS) catalyzes the aminoacylation of tRNA(trp) with tryptophan and is induced by interferon. TryptophanyltRNA synthetase belongs to the class I tRNA synthetase family. Four transcript variants encoding two different isoforms have been found for this gene.