Möllerström et al. BMC Cancer 2010, 10:296 http://www.biomedcentral.com/1471-2407/10/296 Page 8 of 11 Figure 5 Variation of the predictive power depending on survival time. The new Cox-regression model containing BTG2 expression, HER2 ex- pression, patient age and Ki67 expression performed better, i.e. revealed higher prediction accuracy, than a Cox-regression model containing the cur- rently used prognostic markers that gained statistical significance (HER2 expression, and patient age). This difference in predictive power was stable, independent of survival time. patients in the current investigation. The strongest corre- lations in protein expression were between ADIPOR1 and ADORA1, as well as BTG2 overall expression and BTG2 cytoplasm expression. The BTG2 correlation was expected since BTG2 overall expression is a combination of BTG2 cytoplasm expression and BTG2 membrane spe- cific expression. The correlation between ADIPOR1 and ADORA1 is however difficult to explain since they to our knowledge do not interact, although both were expressed in similar proportions of the samples in this study (Table 3), and they are located at 1q32, within 300 000 base pairs from each other. This correlation might be interesting for further investigation. Conclusions We conclude that high BTG2 expression levels correlate with prolonged breast cancer survival. Furthermore, BTG2 protein expression may be used as a prognosticator for breast cancer as well as a possible molecular target in breast cancer treatment. Further studies in independent