MTOR and posterior cortical atrophy: Network robustness is one of the five types of resistance mechanisms described by Glickman and Sawyers, and it typically operates on short-term timescales through feedback loops and other mechanisms that maintain oncogenic driver signaling.45 Using a systems pharmacology approach we perturbed a metastatic PCa model using small molecule inhibitors against AR and PI3K-AKT-mTOR signal transduction pathways.