ERBB2 and neoplasm: In the case to case comparison only BMI >29 kg/m2 revealed a relative stronger connection with positive than with negative HER-2/neu tumours (ratio of OR's = 2.23, 95%C.I: 1.20–4.15, p = 0.011) and this may indicate an evidence of heterogeneity of a rather significant degree for this factor.