In this issue of CRM , Gallone et al. present data from propensity-matched cohorts extracted from three registries to examine the benefit, if any, of the polymer-free biolimus-eluting stent (BioFreedom; PF-BES) as compared to the biostable-polymer zotarolimus-eluting stent (ZES) Resolute in the treatment of coronary bifurcation lesions [ ]. The primary endpoint for the study was a comparison of the major adverse cardiac events (MACE) at 400 days' follow-up between the two propensity-matched groups. As usual, even with propensity matching, one must be cautious in interpreting these data given the non-randomized and retrospective nature of this study.