Alignment of PB1‐F2 sequence from two avian IAV strains (VN (H5N1) and Sha (H7N9)) and two mammalian/human IAV strains (PR8 (H1N1) and Wyo (H3N2)) (Combet
et al,
2000). * above the sequence shows a conserved amino acid between the four strains while ↑ on the bottom shows a different amino acid for PR8 in comparison with the other strains.