Figure 1F. [doi:10.1083/jcb.200612023] Copyright: This image is from Provot S; Zinyk D; Gunes Y; Kathri R; Le Q; Kronenberg HM; Johnson RS; Longaker MT; Giaccia AJ; Schipani E, "Hif-1alpha regulates differentiation of limb bud mesenchyme and joint development." J Cell Biol 2007 May 7;177(3):451-64 [PMID:17470636] , and is displayed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License http://creativecommons.org/licenses/by-nc-sa/3.0/.