We concluded that in the GM-CSF KO inhalation aerosol model, the courseof MAB infection can be divided into three distinct stages (Fig. 4): phase I, an acute phase from day 0 to day 10post-infection, marked by a logarithmic increase in CFU numbers; phase II, anearly chronic stage from day 10 to day 28, characterized by a significantdecrease in CFUs, reaching ~104 CFU; and phase III, a chronic stateestablished between day 28 and day 90 post-infection, with a steady bacterialload of ~103 CFUs in the lungs. This evidence concerns the gene CSF2 and infection.