Polarity is a shared feature of most cells. In epithelial tissues, apical-basal polarity often coexists, and sometimes intersects with, planar cell polarity (PCP), which orients cells in the plane of the epithelium. From a limited set of core building blocks (e.g. the Par complexes for apical-basal polarity and the Frizzled/Dishevelled complex for PCP), a vast array of polarized cells, tissues and organs are generated. This suggests the existence of little-studied tissue-specific factors that rewire the core polarity modules to produce the appropriate polarized structure. I will discuss our latest work on Meru, which functions as a polarity remodelling factor in asymmetric cell divisions in Drosophila.