EIF5A and colon carcinoma: Overexpression of eIF5A, a protein known to undergo posttranslational modification by deoxyhypusine synthase, induced apoptosis in colon carcinoma cells and was shown to be required for expression of p53 following an induction of apoptosis upon treatment of the cells with actinomycin D. Unhypusinated eIF5A may have pro-apoptotic functions and is rapidly translocated to the nucleus following the induction of apoptotic cell death [22].