JUN and cancer: PARN, a major deadenylase in mammalian cells, can potentially act as a tumor suppressor, given that it is activated by the tumor-suppressor BARD1 and it is involved in the degradation of IL-8, VEGF, c-jun, uPA, c-fos and TNF-alpha mRNAs, the levels of which are generally increased in cancers [22–26].