Up-regulated genes in the lungs of endotoxemic wild-type, but not NOS2-deficient mice. Whole lung tissues from wild-type mice treated with (N = 3), and without (N = 4), endotoxin and from NOS2−/− mice treated with (N = 3), and without (N = 1), LPS were studied. The grey dots show the log2 fold change in gene expression upon LPS exposure; the x-axis represents changes in wild-type mice and the y-axis changes in NOS2−/− mice. The transcriptional profiles revealed a contrasting gene expression of pulmonary Arg1 in wild-type and NOS2−/− mice after LPS challenge: Arg1 expression increased in endotoxemic wild-type mice compared to saline challenged wild-type mice (positive scaling on the x-axis). In contrast, Arg1 expression did not increase in endotoxemic NOS2−/− mice compared to the saline-treated NOS2−/− mice (negative scaling on the y-axis). Arg2 expression increased in both strains after LPS challenge (positive scaling on the x- and y-axis).