Left: black hole masses calculated by means of the fundamental plane as reported by Gültekin et al. (2019), and masses estimated via optical spectroscopy. Right: radio luminosity as estimated from the fundamental plane, and measured radio luminosity. Red circles represent FSRQs, blue squares represent BL Lacs, and orange stars indicate NLS1s. The larger stars with a black edge are the four sources we analyzed. The black dashed line is the bisector.