BDNF and Familial prostate cancer: Current knowledge suggests strongly that epidermal growth factor (EGF) and the neurotrophins – nerve growth factor (NGF), brain derived nerve growth factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin 4/5 (NT-4/5), as well as their tyrosine kinase receptors – epidermal growth factor receptor (EGFR) and members of the trk family (trk A, trk b and trk c) play a significant role in stromal–epithelial interactions during Prostate Cancer pathogenesis [13].