It is an open question if Hax-1 is in fact a destabilizing factor or if its actions in respect to the Pol b transcript consist of mRNA stabilization, possibly coupled with its transport and/or localized translation. The fact that Hax-1 binds to the instability element (the hairpin) and does not bind to the stable mutated transcript suggests a role in mRNA destabilization. However, data concerning the role of Hax-1 in the regulation of vimentin transcript, indicating that it facilitates its transport to the perinuclear space, are rather contradictory to its potential functions in mRNA degradation. Another possible explanation is that Hax-1 may stabilize otherwise unstable mRNAs and facilitate their transport or enhance the translation rate, conferring elevated luciferase levels in respect to mRNA levels.