Given in combination with an immunoadjuvant (granulocyte macrophage-colony stimulating factor [GM-CSF]), NP-S has been shown to induce E75-specific CD8+ T-cells expansion, which is even greater in patients with HER2-low breast cancer [78] and when NP-S is combined with trastuzumab [79], thus indicating a synergism of this combination. This evidence concerns the gene CSF2 and breast cancer.