Consistent with our previous study, ERα was not detected in the poorly differentiated cancers (Collins et al. 2009) and immunoexpression of Ki67 was clearly independent of ERα with an increase in abundance of positive nuclei in poor (sample codes 910/2178) as compared to well or moderately differentiated tissue where co-localisation of ERα and Ki67 was readily detected. This evidence concerns the gene MKI67 and cancer.