A research letter was submitted from a team of investigators,A, B, C, and D. In their covering letter they reported that: A was involved in planning the study, collecting patient samples, and in writing the manuscript; B measured IL-10 polymorphisms and analysed the results; C was involved in supervising the measurement of polymorphisms and in writing the manuscript; D was involved in planning the study and writing the manuscript. The letter was peer reviewed and published.