However, in contrast to Park et al. they observed only a moderate delay in tumor outgrowth and no complete regression in a subset of treated mice., Side by side in vivo comparison of the therapeutic efficacy of anti-neu mAb in both the H2N and the TUBO model would be necessary to exclude that differences in immunogenicity between these tumor cell lines underlie the different outcome of the anti-neu mAb therapy experiments of Stagg et al. and the experiments described here. The gene discussed is ERBB2; the disease is neoplasm.