KLF2 and tuberculosis: Host gene transcriptional signatures can distinguish between tuberculosis disease and other illnesses and are measured in blood, a sample easier to obtain than sputum in children.12, 13, 14 The Cepheid Mycobacterium tuberculosis Host Response prototype cartridge (MTB-HR) is a GeneXpert-based RT-PCR test assessing relative messenger RNA levels from fingerstick whole-blood samples.14, 15 It distinguishes tuberculosis from other diseases based on the expression of GBP5 and DUSP3 (upregulated in tuberculosis), and KLF2 (downregulated in tuberculosis).