ERBB2 and Pleural effusion: 2) For breast cancer, BT474 (metastatic in mouse models; breast invasive ductal carcinoma/duct; ER+/PR+/p53mutated; high Her2 expression; “weakly luminal epithelial like” phenotype in culture; reduced expression of epithelial markers) and MCF7 (very weak metastatic potential in the absence of ectopically expressed oncogenes; breast adenocarcinoma/pleural effusion; ER+/PR+/p53 normal; low Her2; epithelial islands in 2D culture; epithelial markers) were analyzed [20]–[23].