This is a review of Maekawa et al. bioRxiv 293050; doi: https://doi.org/10.1101/352278 posted on June 20, 2018. In this paper, the authors mined the transcriptomes of 50 different accession of wild barley, generating a rich library of natural variants of the MLA immune receptor—a classical nucleotide-binding domain and leucine-rich repeat-containing (NLR) protein. They grouped the MLA variants in two subfamilies with all receptors known to be effective against the powdery mildew fungus grouping in one subfamily.