Compounds inhibiting arginase have shown potential in tumor suppression.181 RRX-001, a small-molecule inhibitor, downregulated not only CD47 on cancer cells but also SIRPα on macrophages and showed hypotoxicity but strong antitumor activity in clinical trials.182 In addition, small-molecule inhibitors have great potential in combination with other oncotherapy strategies. Here, CD47 is linked to neoplasm.