Treatment with budesonide of mice undergoing DRA with already established pulmonary inflammation, decreased both the conventionally assessed inflammation parameters and cathepsin- and MMP-derived fluorescence, providing evidence that FMT allows the quantitative evaluation of the activity of corticosteroids in this recently described experimental model of asthma, both on inflammatory cells pulmonary infiltration and, at least partially, on tissue remodeling. The gene discussed is CTSS; the disease is asthma.