Cestone's first name is never told, although "Gigi" is a derivation of the name "Gianluigi". Former soldier in the Junior Soprano crew, defected to Tony Soprano's crew in 1999 following the execution of Philly Parisi (the acting capo of Junior's crew while Junior was incarcerated). The hit was ordered by Tony as revenge for Philly spreading rumors about Tony's mother with regards to Tony and Junior's feud. Gigi was picked up by Philly from the airport, and Philly drove him home. Before exiting the car, Gigi shot Spoons twice in the head and, deafened by his own gunshots, made off in another vehicle being driven by Paulie Walnuts. Gigi was quickly made part of the inner circle of Tony's crew unlike fellow new member Patsy Parisi. Gigi faced some awkward moments around Patsy as he expressed his grief over the loss of his twin brother Philly.
Gigi made a final transition in 2000 when he was granted the role of capo over the Aprile crew, following Richie Aprile's "disappearance." He was well-received by most of his new crew (Donny K, Vito Spatafore and Eugene Pontecorvo), but Ralph Cifaretto took every opportunity to make his life difficult as he had hoped to receive the promotion himself. It was also Gigi's idea to have Bobby Bacala, Sr. perform the hit on Mustang Sally, in the episode, "Another Toothpick."
In a flashback scene in the episode, "…To Save Us All From Satan's Power," Gigi accompanied Junior to a sit-down with acting boss, Jackie Aprile, Sr., in 1995 following Junior's hijackings of Jackie's trucks.
The stress of putting his children through college and trying to control a resentful Ralphie, combined with constipation following Thanksgiving, induced a fatal heart attack while he was on the toilet.