 This process is also known as cap-independent translation.It has been shown that IRES elements have a distinct secondary or even tertiary structure, but similar structural features at the levels of either primary or secondary structure that are common to all IRES segments have not been reported to date.In recent years it has become common for molecular biologists to insert IRES sequences into their vectors to allow for expression of two genes from a single vector—for example, a transgene and a fluorescent reporter molecule.