We hypothesized the lack of a definitive functional profile of specific CD4 T cells in TB to be a consequence of two experimental factors: (i) considering subjects with clinically diverse disease states, specifically EPTB and PTB subjects, as representative of a single disease group26, and (ii) restricted knowledge of the functional composition of the T cell response to the vast majority of T cell antigens expressed by Mtb during various stages of its life cycle, with most studies focussing on a few secretory antigens expressed early in infection20–26. The gene discussed is CD4; the disease is tuberculosis.