Changing a single letter, or base, in an organism’s genetic code impact its traits. Subtler changes can and do happen: in eukaryotes, one such modification involves adding a methyl group to base 6 of adenine (6mA). Researchers report the prevalence of 6mA modifications in the earliest branches of the fungal kingdom. This little-explored realm provides a repertoire of important and valuable gene products for DOE missions in bioenergy and environment.