PknB is a Serine/Threonine kinase that is an essential gene in M. tb. PknB regulates peptidoglycan biosynthesis and other critical biological processes. Inhibition of PknB leads to a reduction in virulence and has bactericidal activity in M. tb. Recent studies have reported that inhibition of PknB in combination with β-lactams results in synergistic activity. TB Alliance researchers have identified selective and potent PknB inhibitors that have activity against M. tb and are not cytotoxic against a panel of mammalian cells.