ARG2 and acute myeloid leukemia: The expression of arginases including ARG1 and ARG2 has been reported to be increased in cancers, such as gastric cancer, breast cancer, prostate cancer, colorectal cancer, and AML (Leu and Wang, 1992; Wu et al., 1996; Porembska et al., 2003; Mumenthaler et al., 2008; Mussai et al., 2013).