CRK and breast cancer: However, stronger EphB2 and EphB4 staining was reported in normal breast glandular epithelium than in tumor epithelium [22], [26], and systemic delivery of ephrin-B2-Fc inhibited the growth of MDA-MB-435 tumor xenografts via EphB4 mediated activation of the Abl/Crk pathway, which inhibits tumor cell growth and motility in breast cancer cells [27].