Earlier studies have reported that the ERAP2 protein encoded by haplotype B undergoes nonsense-mediated decay [25], but more recent work has shown that virally-infected cells (with influenza or HIV-1) can trigger distinctive short transcripts of ERAP2 (termed ERAP2/Iso3 and ERAP2/Iso4) from haplotype B that could partially replenish the loss of ERAP2 expression [17,47]. This evidence concerns the gene ERAP2 and influenza.