ARG1 and infection: As expected, infection resulted in a significant increase not only in protein expression of NOS 2 (0.384 ± 0.149 versus 0.006 ± 0.0016 NOS2/GAPDH, P = 0.029), but also in arginase 1 (1.97 ± 0.29 versus 0.71 ± 0.24 Arg 1/GAPDH, P = 0.01) and arginase 2 (1.11 ± 0.08 versus 0.44 ± 0.04 Arg 2/GAPDH, P < 0.0001) in lung (n = 6 per group) (Figure 1).