In preclinical analyses, a significant increase in VEGFA production was observed in a brain metastases breast cancer cell line (MDA-MB-231-BR) compared with that in the parental cell line (MDA-MB-231), which corresponds to brain metastases lesions with significantly more CD31-positive blood vessels following intra-carotid injection of breast cancer cells in mice21. The gene discussed is PECAM1; the disease is breast cancer.