Thirty-seven breast cancer samples, namely more than half of the breast samples, show amplification with CNV, which means that most of breast cancer samples’ TF coding gene are amplified by CNV, which leads to the high expression of TF gene, thereby positively regulating the PVRL2, so that the expression of the PVRL2 also increases, thereby inhibiting the activity of NK cells and achieving immune escape. This evidence concerns the gene NECTIN2 and breast cancer.