These findings are also consistent with those seen in pre-clinical models of breast cancer treated with neoadjuvant anti-PD-1 therapy, in which survival of mice treated with neoadjuvant ICI was greatest among those with the highest level of tumor-specific CD8 + T cells, suggesting that the antitumor efficacy of neoadjuvant ICI may be heavily reliant on the ability to both increase and maintain elevated levels of CD8 + T cells within the primary tumor26. This evidence concerns the gene PDCD1 and breast cancer.