ERBB2 and cancer: The 61 kDa fragment, like the full-length protein, can bind directly to Plexin D1 to activate cell signaling; such binding has been shown to contribute to cancer cell invasiveness and metastatic spreading by transactivating erythroblastic leukemia viral oncogene homolog 2 (ErbB2) or epidermal growth factor receptor (EGFR) oncogenic tyrosine kinase receptors in colon cancer cells [6] or by inducing nuclear localization of zinc finger protein Snail1 in ovarian cancer cells [7].