>sp|P63231|M2_I72A2 Matrix protein 2 OS=Influenza A virus (strain A/Udorn/307/1972 H3N2) GN=M PE=1 SV=1 MSLLTEVETPIRNEWGCRCNDSSDPLVVAASIIGILHLILWILDRLFFKCIYRFFEHGLKRGPSTEGVPESMREEYRKEQQSAVDADDSHFVSIELE