NPL and infection: In contrast, other key infection genes1 are expressed at very low levels, as is the case of NPL and CBS1, or absent: RPG was undetectable in Dalbergioid legume species and FLOT genes were completely missing in Aeschynomene spp., suggesting mechanistic differences in the infection process (Fig. 2a, Supplementary Fig. 12, and Supplementary Data 2).