The Frangipani Chapel was constructed as a family burial chapel. At the bottom of each of the side-walls are three marble portrait busts, of members of the Frangipani family, set into circular niches. Beneath each statue is an epitaph inscribed with biographical details of the deceased. On the left wall are the statues of Antonino the father (1546) and of his two sons, Curzio (1555) and Mario (1569), the latter of whom had commissioned the decoration.