CEST MRI provides many different clinically promising contrasts. The best studied is Amide Proton Transfer-weighted (APTw) CEST MRI in brain tumors. However, even for APTw in brain tumors many protocols are out there, often with different rf saturation powers, rf duty-cycled and durations, or with different post processings and visualizations. In this article CEST researchers of various groups tried to nail down a single (well almost) protocol that defines APTw for brain tumor imaging.