Additional support for EphB4 and ephrin-B2 involvement in breast cancer is provided by PP2A (protein phosphatase) knockdown effects on ERK pathway in ephrin-B2 stimulated cells [43] and morphological changes in mammary gland as well as aberrant expression of E-cadherin in mutant ephrin-B2 transgenic mice [44]. The gene discussed is EPHB4; the disease is breast carcinoma.