Sitting en banc, the Eleventh Circuit unanimously held in SmileDirectClub, LLC v. Battle, 2021 U.S. App. LEXIS 21393 (11th Cir. July 20, 2021), that an interlocutory appeal may not be taken under the collateral order doctrine from the denial of the state-action antitrust immunity conferred by Parker v. Brown, 317 U.S. 341 (1943). The case…