Giovanni Arrivoli, a boss from the Pagato-Amato crime family of the Camorra or Neapolitan Mafia, has been gunned down as reported by the Daily Mail: "Arrivoli was born a female . . . but the 41-year-old underwent gender reassignment surgery to become a man." The mobster was accepted in the underworld as a man, and there is no suggestion that the hit was over his gender.
Further reading that may be of interest: