In accordance with the effect of D6 on tumor regression, D6 therapy suppressed the EGFR signaling activity: determined by immunoblotting analysis of isolated xenografts, D6 suppressed EGFR expression and relevant downstream effectors, e.g., (pS473)AKT and pERK1/2 (Fig. 6e, f). Here, EGFR is linked to neoplasm.