ERN1 and neoplasm: Indeed, it is likely that in XBP1+/RIDD− tumors, inhibition of IRE1 RNase with small molecules (Hetz et al, 2013) or selective inhibition of the XBP1 mRNA ligase RtcB (Jurkin et al, 2014; Kosmaczewski et al, 2014; Lu et al, 2014; Ray et al, 2014) might lead to significant impairment of tumor growth.