sentence: However , the regulation of the selenoproteome appears to be more complex as there is no obvious correlation between the reported binding properties of SBP2 and the UGA recoding efficiencies that we observed , suggesting the involvement of additional cis - or trans-acting factors.The most surprising finding from our study was the identification of a small group of SECIS elements , including Gpx3 , Gpx6 , SelH , SelO , SelS and Trxr3 , that directed UGA recoding with extremely low efficiency both in vivo and in vitro .