From oral argument in 11-204. Christopher v. SmithKline Beecham Corp.:

MR. CLEMENT: I would start by citing — I know it’s not always in fashion to cite lower court opinions, but I would start by citing Judge Posner’s opinion in Yi, because the Seventh Circuit there, a, a very distinguished panel, Judge Posner, Judge Wood, and one other judge, the three of them considered this question — Judge Sykes, I’m sorry; it slipped my mind, a very distinguished judge.
(Laughter.)