Figure 6
![Figure 6](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1471-2105-7-89/MediaObjects/12859_2005_Article_828_Fig6_HTML.jpg)
Phylogeny of retinoid binding proteins. Cellular retinoic acid binding protein (CRABP) subfamilies I and II and cellular retinol binding protein (CRBP) subfamilies I – IV are boxed. Extant and ancestral amino acids corresponding to alignment site 7 (PDB:1opbA position 4) are shown at leaf and internal nodes.