In stem cell populations, proliferation and differentiation are finely balanced to ensure that the stem cells are maintained but do not overgrow and that non-renewable tissues are generated as required. On p. 93, Hansen et al. report that in the C. elegans germline, the accumulation pattern of GLD-1, an RNA-binding protein, controls the spatially determined balance between proliferation and meiosis. They show that at the distal end of the gonad, a low GLD-1 concentration allows stem cell proliferation; whereas, at more proximal regions, a high GLD-1 concentration promotes the entry of stem cells into meiosis and, ultimately, differentiation into gametes. To explain the accumulation pattern of GLD-1, the researchers propose that GLP-1/Notch signalling and FBF (a homologue of the Drosophila RNA-binding protein Pumilio) inhibit GLD-1 accumulation distally, while NOS-3 (a homologue of the Drosophila translational regulator Nanos) and the poly(A)polymerase GLD-2 act redundantly to promote GLD-1 accumulation proximally.