We agree with Zavras and colleagues that IGF2R, by sequestering IGF2 without transmitting a mitogenic or survival signal, might be a molecule that serves to restrict proliferation. This view is consistent not only with the studies they cite1,2, but also with other work (for example, REFS 3,4,5). Further translational studies to define the influence of germline variation of IGF2R on cancer risk as well as the impact of variation in the number or function of IGF2Rs on cancer cells or neoplastic behaviour will be of interest.