VEGFA and breast cancer: Activator protein 4 represents a helix-loop-helix transcription factor that upregulates serum levels of various cellular and viral genes through binding to particular sites, and it is these specific enhancer sites that modulate expression of VEGF.52,53 It has been shown that the +936T allele associated with reduced levels of VEGF abrogates activator protein 4 located in +936C allele, and thereby results in reduced VEGF expression.13 The +936T allele was also shown to have major effects on decreased uptake of 18F-fluorodeoxyglucose, a marker used to detect and diagnose breast cancer.54.