Cell polarity is regulated by protein networks in the apical and basolateral domains that repress one another by mutually antagonistic interactions. Gamblin et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201803099) reveal that apical Crumbs is antagonized by oligomerization of basolateral Yurt, while Yurt oligomerization is in turn negatively regulated by the apical kinase aPKC.