Insect studies provide additional examples of immunological novelty, at the ordinal, family, or even genus level. One example is provided by Drosophila and Anopheles, both in the same order (Diptera), but representing very different life styles and having been separate lineages for 250 million years. Gene families involved in immunity have evolved rapidly and divergently in the two dipterans. For example, with respect to thioester containing proteins (TEPs), Anopheles has 10 genes and Drosophila only four, with only one orthologous pair between the two. Anopheles has 58 fibrinogen-like immunogenes whereas Drosophila has only 14, with only two shared orthologous pairs (Dong and Dimopoulos, 2009) .