Two new trees have been made with CYP4 sequences as the main content. These trees illustrate the difficulty of maintaining a sensible nomenclature when families get very large. There are some inconsistencies. The 4D subfamily has been split over time into two different clusters of sequences. Cyp4p should probably be in a separate family. The 4F subfamily has also been split. I have started using double letters as in Cyp4aa1 for new subfamilies because the single letters have all been used. Please go the the Drosophila section to see these new trees.