In Reply.—We appreciate the comments by Dr Hawkins and want to emphasize that the key to all of them is the need to use appropriately commutable material for comparison across platforms, especially in this era of nonstandardized hospital systems, where there is an urgent need to have some form of comparability across said systems. We stand by the facts that the best material for this project is ultimately patient samples and that proficiency testing material shouldn't be used for this exercise.