Quoting and citing a handful of pre-Gall decisions from other circuits, the Pugh panel noted in dicta that " '[a] sentence may be substantively unreasonable when,' " among other reasons, the district court "bases the sentence on impermissible factors." 515 F.3d at 1191-92 (quoting Ward, 506 F.3d at 478, and citing United States v. Ausburn, 502 F.3d 313, 328 (3d Cir. 2007), United States v. Willingham, 497 F.3d 541, 543-44 (5th Cir. 2007), and United States v. Boleware, 498 F.3d 859, 861 (8th Cir. 2007)). The panel never offered any of its own reasons why consideration of an impermissible factor should be viewed as bearing on a sentence's substantive (as opposed to procedural) reasonableness.