Notwithstanding, as the very early signaling events generated by Tz in targeted cells are poorly studied, we performed biochemical and morphological analyses in the ERBB2 overexpressing breast cancer cell line SK-BR-3 to determine the ERBB2 and ERBB1 signaling contribution in the context of an ERBB2/ERBB1 heterodimer. The gene discussed is EGFR; the disease is breast cancer.