The columns are supported by lions in white marble. It has reliefs with "Christ Crowned by Saints" and "Birth of the Baptist". Isabello's Renaissance porch has, in the lunette, a fresco of "Mary's Nativity" attributed to Andrea Previtali. The interior has maintained the original Romanesque Greek cross plan, with a nave and two aisles divided by piers and ending with an apse, but the decoration its largely from the 17th century Baroque renovation. On the walls are tapestries, partly executed in Florence (1583–1586) under Alessandro Allori's design, partly of Flemish manufacture, depicting the "Life of Mary". Over the tapestry of the "Crucifixion" (executed in Antwerp on Ludwig van Schoor's cartoons, 1698) is a painting by Luca Giordano, with the "Passage of the Red Sea" (1691). Left to the entrance is the sepulchre of Cardinal Guglielmo Longhi, work by Ugo da Campione (1313–1320). On the rear wall are the tomb of the composer Gaetano Donizetti, by Vincenzo Vela (1855) and that of the latter's master Simone Mayr (1852). At the beginning of the left aisle is the Baroque confessional carved by Andrea Fantoni in 1704. A crucifix from the 14th century is on the presbytery's balustrade. In the presbytery itself, housing six bronze candelabra from 1597, is a wooden choir designed by Bernardo Zenale and Andrea Previtali. The reliefs with Biblical tales were executed in 1524–1555 on designs by Lorenzo Lotto. They are characterized by a polychrome effect rendered through the use of different wood types. The right transepts has Giottesque frescoes from an unknown artist, with "Histories of St Aegidius", "The Last Supper" and the "Tree of Life" (1347), partially covered by a 17th-century fresco.