Data on hadron production at high transverse momentum (p T > 2 GeV/c) in p+p, d+Au, and Au+Au collisions at % MathType!MTEF!2!1!+- % feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaOaaaeaaca % WGZbWaaSbaaSqaaiaad6eacaWGobaabeaaaeqaaOGaeyypa0JaaGOm % aiaaicdacaaIWaaaaa!3C0E!]]</EquationSource><EquationSource Format="TEX"><![CDATA[$$\sqrt {{s_{NN}}} = 200$$ GeV from the PHENIX experiment at RHIC are reviewed. The single inclusive spectrum of light hadrons produced in central Au+Au reactions shows significant differences compared to p+p and d+Au collisions, and provides interesting information on the properties of the underlying QCD medium present in heavy-ion reactions at collider energies.