ERBB2 and neoplasm: Therefore, to assess the independent prognostic influence of ER, PR, Her2 and Bcl-2 and to investigate whether the relationship between grade and Her2 status is consistent across all levels (i.e., a tumour that is Her2 positive is most likely to be HG, less likely to be of IG and least likely to be of LG), we performed an ordered logistic regression analysis with grade (LG, IG and HG) as the three-level dependent variable and ER, PR, Her2 and Bcl-2 as binary (positive/negative) explanatory variables.