Infection with Mtb evokes dynamic innate and adaptive cellular and humoral immune responses, and currently available tests capture this complexity to a very limited extent.1,16,17 Skin induration is an in vivo delayed-type hypersensitivity reaction18 while IGRA measures ex vivo IFN-γ reactivity to ESAT-6, CFP-10 and TB7.7(p4) by immune cells.17 Thus, TST assesses a much wider range of both innate and acquired immune components18 than IGRA, which represents a narrow, antigen-specific T-cell response. This evidence concerns the gene IFNG and infection.