VTCN1 is a kind of transmembrane protein with 282 amino acids, consisting of a transmembrane domain, a two amino acid intracellular domain and seven N-glycosylation site extracellular domain (78), which is a type of minority immune checkpoint that is expressed on the surface of tumor cells like serum ovarian cancer and breast cancer (79). This evidence concerns the gene VTCN1 and breast cancer.