The diagram highlights potential biomarkers that can aid in patient selection for arginine deprivation anticancer therapy. These biomarkers encompass lower levels of ASS1 and WWOX proteins in tissues (red arrow pointing down), in addition to increased expression of HIF-1 protein (red arrow pointing up). Furthermore, genetic variations, including mutations in the BAP1 and BRAF genes, as well as single nucleotide polymorphism (SNP) variations, specifically WWOX-rs13338697 and rs6025211, may also serve as biomarkers. Additionally, pre-treatment and post-treatment circulating arginine levels can be used to predict the therapeutic efficacy of this therapy for cancer treatment. Patients highlighted in gray may not respond to arginine deprivation therapy, while those in green may potentially have a positive response to this therapy. Abbreviation: ASS1, arginosuccinate synthetase 1; HIF-1, hypoxia-inducible factor-1, WWOX, WW-domain-containing oxidoreductase; BAP1, BRCA1 associated protein 1; BRAF, B-Raf proto-oncogene, serine/threonine kinase.