The team of Hernan Mejia-Renteria and Javier Escaned and other international collaborators have carried out a nice study on the influence of microcirculatory dysfunction of physiologic assessment by QFR. This is a topic of high importance and interest. The comparison was with FFR used as the reference standard. They concluded that in the group with high-IMR a significantly lower classification agreement and area-under-the-curve was found relative to the low-IMR group. But despite that, even in the presence of coronary microvascular dysfunction, QFR remains superior to angiography alone in ascertaining functional stenosis severity.