Arginase 1 protein expression in blood serum has recently been associated with markers of oxidative stress in a healthy human population [45], and augmented arginase activity correlates with indices of oxidative stress (i.e., malondialdehyde and protein carbonylation levels) in platelets and plasma from patients with chronic obstructive pulmonary disease exposed to wood smoke [46]. Here, ARG1 is linked to chronic obstructive pulmonary disease.