ISG15 and bacterial infectious disease: Taking into account that the intracellular survival of Mycobacterium tuberculosis depend on its ability to arrest phagolysosome biogenesis blocking the efficient antigen processing and presentation in macrophages [46], it is likely that this novel mechanism described here might also play a role in the increased susceptibility of ISG15 deficient humans to bacterial infections, although further investigations will be needed to evaluate this possibility.