ZFP36 proteins have been postulated to act as tumor suppressors.50,51 A large proportion of ARE-containing transcripts are considered mitogenic, and ZFP36 loss leads to a rise in their abundance.52 Interestingly, although we observed ZFP36 family member induction in response to growth factor stimuli within cancer cell lines, the dynamic range of expression was modest relative to normal immortalized cells of similar origin. This evidence concerns the gene ZFP36 and cancer.