Fig. 2.

Part of a panel of Kaplan-Meier survival curves (17). Note the dotted curve crossing other 2 curves. This clearly violates the “proportional hazard” assumption made in Cox proportional hazards model (re-used with permission in accordance with the terms of the Creative Commons Attribution Non-Commercial License [http://creativecommons.org/licenses/by-nc/3.0/]).

MELD = model for end-stage liver disease.