The sum of results from (i) the analysis of the clinical cohort (reduction of metastatic risk in ERBB2 tumours), (ii) the experiments performed in vivo (reduced tumour masses, reduced ‘metastatic’ ability and decreased expression of EMT markers in the animal model) and (iii) in vitro (reduced protrusive ability of acini and restoration of polarity in the 3D-morphogenetic assays), points to a counteraction of p140Cap on ERBB2-dependent tumour progression. This evidence concerns the gene ERBB2 and neoplasm.