We measured serum levels of the pro-angiogenic vascular endothelial growth factor A (VEGF), and placental growth factor (PlGF) and anti-angiogenic soluble fms-like tyrosine kinase-1 (sFlt-1) in 352 incident breast cancer cases [mean age at diagnosis 67 (range 55–83)] and 352 non-cases in the prostate, lung, colorectal, and ovarian screening trial (women enrolled 1993–2001, followed through 2005) matched on age and date of enrollment. The gene discussed is PGF; the disease is breast cancer.