Viral 2A “self-cleaving” peptides benefit studies that require co-expression of multiple proteins from a single transgene. These peptides have relatively high efficiency in skipping and re-commencement of translation, resulting in two “cleaved” proteins: the protein upstream of the 2A is attached to the 2A peptide without the C-terminal proline, the protein downstream of the 2A is attached with one proline at the N-terminus. The small size of 2A also lowers the risk of interfering with the co-expressed protein (Liu et al., 2017).