CXCR4 and breast cancer: PEDF can decrease phosphorylated-nuclear factor-kB p65 subunit (p-NFkB-p65), tumour necrosis factor- (TNF), C-X-C chemokine receptor type-4 (CXCR4), and urokinase plasminogen activator receptor (uPAR) in ER+/HER2- breast cancer cells under post-menopausal oestrogen concentrations [17].