HLA-G and breast cancer: In 2020, Schwich et al. reported that soluble HLA-G can induce a an immunosuppressive/exhausted phenotype, and the purified soluble HLA-G1 protein or extracellular vesicles derived from an HLA-G1-positive human breast cancer cell line, SUM149, can affect the anti-tumor function of CD8+ T cells by binding to ILT-2 (73).