ESX1 and infection: However, taking into consideration that the reported ESX-1-dependent type I interferon response to infection with M. tuberculosis occurs already 24 h post infection [33], it is plausible that rupture of the phagosomal membrane is preceded and/or initiated by pore-forming activity of ESAT-6, which might allow small signalling molecules such as cyclic diadenosine monophosphate (c-di-AMP) [54] or other PAMPs to translocate prior to the escape of entire bacteria and thereby trigger an early cytosolic host response.