The Hnf gene family is part of the HNF homeobox class. The Hnf gene family contains two human genes: HNF1A and HNF1B. The use of the suffixes A and B does not indicate recent origin in this case; the two genes were generated by genome duplication early in vertebrate evolution. There is one orthologue in amphioxus (Tcf or Hnf1). Drosophila lacks the gene family; this is secondary loss, because the gene family is present in the cnidarian Nematostella vectensis (Holland et al. 2007).|
Holland PWH, Booth HAF, Bruford EA (2007) BMC Biology 5:47.