The tumour suppressor protein APC, which is mutated in most colorectal cancers, prevents tumorigenesis by inhibiting Wnt signalling. It also regulates cell adhesion and migration through interactions with the plasma membrane and microtubules. Jürgen Behrens and co-workers now identify a novel membrane-associated protein, AMER1, that recruits APC to the plasma membrane (see p. 3738). They show that localization of AMER1 to the plasma membrane depends on two lipid-binding domains in its N-terminus and that AMER1 interacts with the armadillo repeat domain of APC. Overexpression of AMER1, they report, increases APC levels, recruits APC to the plasma membrane and prevents interaction of APC with microtubules. Conversely, knocking down AMER1 by RNAi increases the association of APC with microtubules and disrupts intercellular junctions. This work provides exciting new information about how the subcellular distribution of APC (and consequently its regulation of Wnt signalling, cell migration and cell-cell adhesion) is controlled. Moreover, it reveals how mutations in AMER1, which turns out to be identical to WTX, a tumour suppressor mutated in Wilms tumours, might promote tumorigenesis.