Kaplan-Meier curves illustrating OS after transplant based on risk groups defined by the prognostic models. (A-B) Kaplan-Meier plots showing OS according to the Cox regression statistical model in the training (A) and test (B) sets. (C-D) Kaplan-Meier plots displaying OS according to the ML model in the training (C) and test (D) sets. Patients were split according to the predicted quartile of risk. Each branch represents a quartile of patients with either low (blue), intermediate-low (green), intermediate-high (orange), and high risk (red).