PURB and tuberculosis: Numerous targets that are highly vulnerable in Mtb have yet to be pursued, including targets significantly more vulnerable than the current first-line TB therapies and in underexplored processes such as protein folding (groES and groEL2) and secretion (secYE), metabolism (nadD, dxs1, aroF, and purB), chromosome replication (dnaE1 and dnaA), and cell division (ftsZ).