ARG1 and asthma: To investigate whether the presence or absence of ARG1 activity affected the adaptive responses to OVA-induced asthma in a quantitatively similar way, we also investigated to what extent changes in lung-function parameters, mRNA and protein concentrations, histology quantitation and plasma amino-acid concentrations correlated in either Arg1-Con or Arg1-KOTie2 mice (Fig. 8).