Future studies will require single cell resolution, using single cell sequencing or multiplex RNA FISH assays, to confirm the source and spatial organisation of exaggerated IL-17A/F responses in this model, as well as to determine whether active TB shows enrichment for ‘pathogenic’ Th17 cells that express both IFN-γ and IL-17A/F (69). The gene discussed is IL17A; the disease is tuberculosis.