Ah, I don't see those as the issues (at least in a generalist puzzle) - a ligament is a 'a physical connection or bond', which fits the dictionary definition of a tendon, 'tissue that attaches a muscle to a bone or some other part'; and antigens I believe can be used in the treatment of certain medical conditions. But a recipe is not something you eat, it's a list of ingredients and directions; and 'treat' in the sense of 'apply treatement to' is a transtitive verb and must have an object, which it has here in the surface reading but not in the definition - as an intranstivie verb it means 'to negotiate'.