The Hippo signalling pathway, a conserved tumour suppressor pathway, is involved in other developmental processes in addition to proliferation control. For example, Hippo signalling in the posterior follicle cells (PFCs) of Drosophila ovaries is required for oocyte polarisation. Now, Trudi Schüpbach and colleagues report that a phospatidylinositol 4-kinase (PI4KIIIalpha), which catalyses the production of membrane phospholipids, is required in PFCs for oocyte polarisation and Hippo signalling (see p. 1697). The researchers isolated mutations in CG10260, which encodes PI4KIIIalpha, while screening for Drosophila genes required in follicle cells for oocyte polarisation. They show that PI4KIIIalpha loss in PFCs leads to oocyte polarisation defects similar to those caused by mutations in the Hippo signalling pathway, and that PI4KIIIalpha mutations cause misexpression of Hippo targets. Notably, the apical membrane localisation of Merlin, which is required for Hippo signalling, is lost in PI4KIIIalpha mutant PFCs, presumably because of changes in the cell membrane's lipid composition. Together, these data reveal a new link in the Hippo signalling pathway.