TXNRD1 and colorectal adenocarcinoma: Interestingly, mRNA levels of two selenoenzymes, GPx2 and TrxR1, were previously shown to be elevated upon activation of Nrf2 [11,12]; moreover, synergistic induction of GPx2 and/or TrxR1 by the Nrf2-activating electrophilic compound sulforaphane (SFN) and Se was shown to protect Caco-2 human colorectal adenocarcinoma cells and HepG2 human hepatoma cells against oxidative stress-mediated cell death [13,14].