D. Doak Horne LLB, PEng is a partner in Gowling WLG's Calgary office. The focus of his practice is intellectual property litigation, particularly in relation to patents, including patent prosecution before both the Canadian Intellectual Property Office and the USPTO. Doak has appeared as lead counsel in actions involving patent infringement and impeachment, trademark infringement and expungement and oppositions, copyright infringement, trade secret litigation, as well as passing off actions, at all levels of Federal and Provincial Courts (Alberta and Ontario), most recently on behalf of the successful defendant in Betser v. PetroChina Canada Ltd. 2021 FC 85. He is also involved in the preparation, filing, and prosecution of patent, trademark, and industrial design applications for clients in Canada and the US, and provides opinions in clearance-to-use/freedom-to-operate matters, patent validity, as well as licensing matters and related contractual agreements. Prior to his legal career, Doak worked as a mechanical engineer in jet engine design. Doak has been long recognized in The Canadian Legal Lexpert® Directory and TheBest Lawyers in Canada. In 2014, he was recognized by Best Lawyers Canada as Lawyer of the Year for Intellectual Property Law – Western Canada.