Objectively, analysis of public breast cancer datasets revealed a considerably higher arginine level in cancer tissues harboring high expression of EI24 (Fig. 1G), and EI24 linked to the enrichment of arginine_and_proline_metabolism (Fig. 1H), while gene expression data from OncoDB suggested an overall reduction of both ASS1 and EI24 in tumor compared with normal (Supplementary Fig. S1D). Here, ASS1 is linked to breast cancer.