HOTHEAD is an Arabidopsis thaliana gene that encodes a flavin adenine dinucleotide-containing oxidoreductase. This gene has a role in the creation of the carpel during the formation of flowers through the fusion of epidermal cells.[1] Observations of reversion of the hothead phenotype and genotype led to the suggestion that the plants were able to "remember" the sequences of genes present in their ancestors, possibly through a cache of complementary RNA.[2] This report attracted broad attention,[3] and alternative explanations were suggested.[4][5][6] Later research suggested that the supposed reversion phenomenon was due to the plants having a pronounced bias towards outcrossing (because of their floral defects), rather than self-fertilizing at high rates, as is typical for A. thaliana.[7][8][9][10]