While some of the immunodominant antigens (eg, 38kDa PhoS protein) are specific to cavitary TB [6], [8], [19], others, such as the 81-kDa Malate Synthase (MS) (Rv1837c) and the 29-kDa MPT51 (Rv3803c) elicit antibodies in patients at different stages of clinical TB (smear-negative or positive TB; non-cavitary or cavitary TB) and in different classes of TB patients (HIV−TB+ or HIV+TB+) [8], [9], [20], [21]. The gene discussed is CLYBL; the disease is tuberculosis.