Properties of pathway-based priors. Priors are encoded by functions f1(γ) (number of pathways) and f2(γ) (intra-pathway distance). Shaded components are contained in model γ and shapes represent different pathways. Top row: Comparisons of the scoring functions. Top left - γ1 has larger intra-pathway distance than γ2; Top middle - distance is agnostic to number of pathways; Top right - addition of a singleton has no effect on distance. Bottom row: The root component in each network is in both pathways. However, f1(γ) is defined so as to avoid double counting.