Vatican Files via Triablogue:
After noting that it is the common opinion of Protestants that the Pope is the Antichrist, Turretin explains that Scripture reveals the place of the Antichrist (the temple), his time (from apostolic times onward), and his person (an apostate from the faith, a performer of spurious miracles, one who opposes Christ, a self-exalting figure, a man of sin, an idolater). Turretin goes as far as analyzing the name and number of the Beast of Revelation 13:17-18. Gathering all these elements together, he does not find these marks among the Jews or Turks (Muslims), nor among the Greek Orthodox. In his view, they only fit the chief authority of the Roman Church.
Turretin is convinced that the Antichrist is not a single person but must refer to an office or succession of persons in office that began operating in apostolic times. To the Catholic objection that Popes have never denied Christ, Turretin replies that the Antichrist will not openly deny Christ as a professed enemy but as a professed friend of Christ who praises Him with their words, yet fights Him with his actions. He sees this attitude in Popes who arrogate to themselves the three offices of Christ (Priest, Prophet and King), but bury the Gospel under their own traditions and undermine His work of redemption by their masses, purgatory, indulgences, and false worship.