 The first gene is initiated at the normal 5' cap, and the second gene is initiated at the IRES.IRESs are commonly located in the 5'UTR of RNA viruses and allow translation of the RNAs in a cap-independent manner.However, mRNAs of viruses from "Dicistroviridae" family possess two open reading frames (ORFs), and translation of each is directed by two distinct IRESs.