Recently, a phase I clinical trial of the first monoclonal antibody (NC318) targeting SIGLEC15 showed that patients with advanced/metastatic solid tumors with PD-L1 tumor proportion score (TPS) <50% and refractory or resistant to existing therapies could benefit from anti-SIGLEC15 treatment (NCT03665285). Here, SIGLEC15 is linked to neoplasm.