Metal-insulator transition and possible ferromagnetic instability in two dimensions Sergey Kravchenko Northeastern University Boston For nearly 20 years, it had been the prevailing view that there could be no metallic state or metal-insulator transition (MIT) in two-dimensional electron systems in zero magnetic field. However, in the last few years, unusual behavior suggestive of such a transition has been reported in a variety of strongly-correlated two-dimensional electron systems. Although the physics behind these observations is not yet understood, it has become evident that the interactions between electrons are playing the key role. Recent observation of sharply increasing spin susceptibility in the immediate vicinity of the MIT suggests that the transition may be related to a spontaneous spin polarization (ferromagnetic instability). I will review the main experimental results and suggested explanations of these phenomena.