however , ferrets immunized similarly with recombinants expressing the h1 haemagglutinin , neuraminidase ( n1 or n2 ) , polymerases ( pb1 , pb2 or pac ) , matrix protein ( m1 or m2 ) , nucleoprotein ( np ) or non-structural proteins ( ns1 or ns2 ) were completely susceptible to the influenza virus .
C0033684
protein
C0028612
nucleoprotein