VSIR and breast cancer: HMB-002 is an IgG4 type antagonistic monoclonal antibody against VISTA that does not rely on Fc. It was developed under the guidance of AI and targets a conserved specific functional epitope on the C-C ‘ring specific to VISTA. It has shown effective inhibition of tumor growth in humanized mouse cancer models of preclinical colorectal cancer, lung cancer and breast cancer.