Francesco Borromini, a 16 years old in search of fame and fortune, was in charge to chisel the cherubs' heads at the entrance hall of Basilica of St. Pietro, still visible on the sides of the main gate. He made such a wonderful job that he gained popularity. Not a lot of people know it but after this experience, Borromini included these cherubs' heads in almost all of his works, for example in Quattro Fontane of St. Carlino, Church of St. Giovanni in Laterano and even at Church of St. Ivo alla Sapienza. They almost became his trademark.