for a sentence reduction because he was sentenced as a career offender. Gibson now appeals the ruling. We are bound by this court’s decision in United States v. Moore “unless and until it is overruled by this [C]ourt en banc or by the Supreme Court.” United States v. Brown, 342 F.3d 1245, 1246 (11th Cir.2003). Where a retroactively applicable guideline amendment reduces a defendant’s base offense level, but does not alter the sentencing range upon which his sentence was based, the District Court is not authorized to grant a sentence reduction pursuant to § 3582(c)(2). Moore, 541 F.3d at 1330. This includes the situation in which a retroactive amendment to § 2Dl.l(c) would result in a lower base offense level, but the defendant was sentenced as a career offender. See id. at 1326-30 (<HOLDING>). Furthermore, we held in Moore that a
holding that while amendment 706 was applicable to the defendants in question because it reduced their base offense levels a reduction was not authorized because the amendment did not have the effect of lowering their applicable guideline ranges because of the application of the career offender guideline holding a reduction in defendants sentence as a career offender was not authorized under  3582c2 because amendment 706 did not lower his applicable guideline range under the careeroffender guidelines holding that while amendment 706 was applica ble to the defendants in question because it reduced their base offense levels a reduction was not authorized because the amendment did not have the effect of lowering their applicable guideline ranges because of the application of the career offender guideline holding that amendment 706 did not have the effect of lowering the applicable guideline range where the defendants received statutory mandatory minimum sentences and thus the defendants were not eligible for relief under  3582 holding that a defendant whose original sentence was based upon the careeroffender guideline and not  2d11 could not receive a sentence reduction based on amendment 706 because it did not have the effect of lowering the applicable guideline range