To address the issue of the gender bias in cases and controls we reanalysed the data to determine whether a classifier based on the proteomic profile could reliably discriminate males from females. This was found not to be the case, suggesting that gender is not a major confounder in our analysis. As a further test, a new classifier was trained on male patients alone, to discriminate active TB from symptomatic controls. When we applied the trained classifier to the female subjects, this classifier was nevertheless still capable of classifying TB to an accuracy of approximately 80%.