Figure 2B. [doi:10.1186/1471-213X-3-6] [PMID:12887734] Copyright: This image is from Maddox DM; Manlapat A; Roon P; Prasad P; Ganapathy V; Smith SB, BMC Dev Biol 2003 Jul 29;3(1):6 an open-access article distributed under the terms of the Creative Commons Attribution License