ABCB1 and tuberculosis: The p-glycoprotein efflux pump inhibitor verapamil has been reported to restore the activity of several first line anti-TB drugs against drug-resistant isolates (Pasca et al., 2004; Srivastava et al., 2010; Machado et al., 2012; Sun et al., 2014) and to potentiate the in vitro activity of newer anti-TB agents bedaquiline and clofazimine on Mtb cultures (Gupta et al., 2014).