The combination of NIR-PIT using the HER2 Affibody-IR700Dye conjugate and the trastuzumab-IR700Dye conjugate has real therapeutic potential for brain metastases of HER2-positive cells because when cancer metastasizes to the brain, the blood–brain barrier (BBB) is disrupted [27], consequently permitting both monoclonal antibodies and Affibody molecules to cross [28,29,30,31]. The gene discussed is ERBB2; the disease is cancer.