In addition, recent clinical observations indicate that early-stage HER2-positive breast cancers that did not react with neoadjuvant combinations such as docetaxel, carboplatin, and trastuzumab with or without pertuzumab demonstrate an immunosuppressive tumor microenvironment phenotypes, and this phenotypic change involves CD4+ and FoxP3+ cells that represent the Treg population (59). This evidence concerns the gene CD4 and breast cancer.