Lady Gaga is using her star power to help out a friend.The singer and actress, who starred alongside Bradley Cooper in A Star is Born, took to Twitter on Monday to encourage fans to see her friend‘s latest film, urging her followers to head to the theater and see Nightmare Alley, a psychological thriller that boasts a star-studded cast.“Nightmare Alley is an amazing film with an amazing cast, congratulations to @RealGDT,” Lady Gaga tweeted.