Grain growth has been a subject of study in the processing and microstructure of materials for many years. Recent advances have focused on three-dimensional topology, three-dimensional microstructure reconstruction and three dimensional kinetic models. Much of our understanding to date is based on assumptions of uniform boundary mobility and surface energy. In this talk I will describe an enhanced framework for study of grain growth when the key factors of mobility, surface energy and curvature are not uniformly distributed in the microstructure. Recently it has been demonstrated that gradients in grain size lead to variations in the kinetic response of microstructures. Efforts to quantify this variation both in experiment and simulation will be presented. We will present hypotheses for mechanisms that might explain why this variation occurs.