When scFv(FRP5)-ETA was directly administered into tumor lesions by intratumoral injection in a previous study, complete regression or partial reduction in the size of injected tumor nodules was found in five out of seven patients with tumors expressing high ErbB2 levels [23], indicating that the antibody toxin can very well selectively eliminate ErbB2-overexpressing target cells if they are accessible. Here, ERBB2 is linked to neoplasm.