The slightly coved (convex) aedicule has bunched Corinthian pilasters in yellow and black-and-white marbles, and these are fronted by a pair of columns in red Sicilian jasper supporting a curved horizontal entablature which is yellow-red-yellow. The pair of arched doorways flanking the altar lead into the choir. There are two large statues of allegorical virtues over them by Fra Secondo. They were installed in 1751.