Like RNAfold, RNAcofold can be used to compute DNA dimers by replacing the RNA parameter set by a suitable set of DNA parameters. At present, the computation of DNA-RNA heterodimers is not supported. This would not only require a complete set of DNA-RNA parameters (stacking energies are available [49], but we are not aware of a complete set of loop energies) but also further complicate the evaluation of the loop energy contributions since pure RNA and pure DNA loops will have to be distinguished from mixed RNA-DNA loops.