THNSL2 (threonine synthase-like 2), also known as TSH2, is a 484 amino acid protein belonging to the threonine synthase family. Utilizing pyridoxal phosphate as a cofactor, THNSL2 may function as a catabolic phospholyase on gamma and beta phosphorylated substrates. THNSL2 may also degrade O-phospho-threonine to alpha-ketobutyrate, ammonia and phosphate. Existing as four alternatively spliced isoforms, THNSL2 is encoded by a gene mapping to human chromosome 2p11.2.