ARG1 and neoplasm: Pairwise analysis showed significantly downregulated expression of ARG1 (by 2.2-fold, p = 0.025), DDAH1 (by 1.4-fold, p = 0.016), and DDAH2 (by 1.6-fold, p = 0.005) and upregulated expression of NOS2 (by 2.6-fold, p = 0.003) in tumor as compared to adjacent, macroscopically normal tissue.