Erica Rutter presents non-parametric techniques for estimating tumor heterogeneity from data. She describes using a Prohorov metric framework to determine the approximate distributions of diffusion (D) and growth (ρ) parameters from data, without assumptions about their distributions. She creates synthetic data from a known ρ distribution and solves the inverse problem to estimate ρ, comparing solutions using delta functions and spline functions with varying numbers of nodes. The Akaike Information Criteria is used to select the optimal number of nodes. Representative results show the estimated ρ distribution matching the true distribution well.