NFKB1 and AL amyloidosis: As well, suppression of hypusinated eIF5A1 using a small interfering RNA (siRNA) has been shown to inhibit activation of Nuclear Factor kappa B (NF-κB) and ERK MAPK in multiple myeloma cells [16] and to potentiate the pro-apoptotic activity of an eIF5AK50R expression plasmid.