Pacitto et al., (2015) have just solved the crystal structure of yeast FNIP orthologue Lst4. Bioinformatics studies had predicted that FNIP1 and FNIP2 are DENN-family proteins (Zhang et al., 2012), like FLCN (Nookala et al., 2012). Pacitto et al. identified a characteristic longin domain, confirming that Lst4 is a DENN-family protein, and showed that Lst4 interacts, via its DENN domain, with the FLCN orthologue Lst7 forming a 1:1 heterodimer. As with FLCN-FNIP heterodimers, Lst7-Lst4 is relocated to the vacuolar membrane under nutrient starvation conditions. This new structure will facilitate process in BHD research and the development of novel therapies. Confirmation of conserved structure and function in the yeast orthologues supports the use of this eukaryotic model for future studies.