Indeed, the Celf1-mediated p27Kip1 post-transcriptional control mechanism described here in the lens may serve to inform on the complexity of p27Kip1 regulation in other developing tissues, and the impact of its mis-regulation on cell growth and cancer, as well as on the pathobiology of other Celf1-associated defects such as myotonic dystrophy. The gene discussed is CELF1; the disease is cancer.