EXTL2 (Exostosin-Like Glycosyltransferase 2) is a gene that encodes an enzyme involved in the production of heparan sulphate, a key component of the extracellular matrix. Heparan sulphate interacts with various growth factors and signalling molecules, playing important roles in cell proliferation, adhesion, and differentiation. EXTL2’s function in heparan sulphate synthesis underscores its importance in development and maintaining tissue health.