ERBB2 and triple-negative breast carcinoma: Taken together, the new experimental therapeutic 4′-nitro-9-aza-glycophymine (19) shows promising in vitro and in vivo efficacy against both hormone receptor- (MCF-7) and HER2/neu-positive (BT-474) cell lines but also to hormone-independent, more aggressive triple-negative breast cancer types (MDA-MB-468, HCC1937 and 4T1).