Fig 1E. [doi:10.1002/dvdy.21423] Copyright: This image is from Ratzka A; Kalus I; Moser M; Dierks T; Mundlos S; Vortkamp A, "Redundant function of the heparan sulfate 6-O-endosulfatases Sulf1 and Sulf2 during skeletal development." Dev Dyn 2008; 237: 339-53. Reprinted with permission of Wiley-Liss Inc. [PMID:18213582]