ESX1 and infection: However, recent reports basedon in vitro infection of phagocytes also suggest that at later stagesof infection ESX-1-dependent vacuolar breakage might be an important requirement for thepathogenic potential of Mtb, given that ESX-1-deficient bacilli thatare unable to perforate and lyse the phagosomal membrane are—ingeneral—attenuated [13,15,16,18,56–59].