ERBB2 and breast cancer: Our previous studies highlighted PEDF downregulation in the presence of post-menopausal oestrogen levels in both ER+/HER2- BC and TNBC cells (manuscript submitted), contrary to expectations that higher circulating E2 levels pre-menopause [61] would have a greater downregulatory effect on PEDF, based on previous studies investigating E2 and PEDF in other tissues [14,62,63].