Phylogeny of PTEN domains. An unrooted maximum likelihood tree of 76 PTEN domains constructed as described in Materials and Methods. For a full list of genes, see Additional files 1 and 7. Only sequences that did not introduce large gaps into the alignment were chosen; for a tree from a larger selection of PTEN domains see Additional file 9. Numbers at nodes denote bootstrap values (out of 500 replicates; branches supported in all bootstraps marked by a dot). For comparison, bootstrap values from a NJ tree constructed on the basis of the same data are shown in green for major branches (from 500 bootstrap samples).