ASS1 and colonic neoplasm: Recently, studies showed that the metabolic supplementation of citrulline, which drives NO synthesis (Kim et al., 2015), together with fisetin, which upregulates ASL and ASS1 levels, is a promising approach to overcoming NO-related tissue and dosage obstacles, and to restrict the development of inflammation-associated colon cancer (Stettner et al., 2018).