Discordant results on the prognostic value of OPG in three datasets. Kaplan–Meier analysis of all patients (A) and the ER positive subset (B) in the Rotterdam dataset according to OPG mRNA expression. OPG was dichotomized using the cutoff derived from its bimodal expression (Affymetrix probeset 204933_s_at). The same cutoff was used for validation in the ER positive subset of the Mainz dataset (C) and Uppsala dataset (D), respectively. Data in panels B, C, and D are shown for the ER positive subset in order to exclude bias from different proportions of ER positive and ER negative samples in the datasets. Similar results were also obtained when including the complete cohorts (Supplementary Figure S10). Distant metastasis free survival was used in Panels A, B, and C. Relapse free survival was used in Panel D. The small inset figures display the bimodal distribution and the applied cutoff.