Before his father's death, Ezio told Sofia to give their son the key to a chest hidden in the catacombs of the Villa Auditore, once he had reached the age of 22. However, as Ezio never told his wife what the chest contained, she suspected Ezio intended to give Marcello an opportunity to become an Assassin, and discarded the key into a river, keeping Marcello ignorant of his heritage.
- Marcello is an Italian diminutive of the name Marcus, derived from the name of the Roman god of war Mars, and as such it is traditionally translated as "like Mars" or "warlike".
- Prince Suleiman I introduced Ezio to Ahmet as "Marcello" to hide his true identity.
- Marcello appears in the Assassin's Creed: Revelations novel, where he accompanies his mother and sister to the market where Ezio dies.