Multiple sequence alignment of cloned human IFNα-2b and subtypes of human interferon alpha. (*) indicates identical amino acids in all sequences, ( : ) indicates conserved substitution, ( . ) indicates semi-conserved substitution. Conserved cystein residues in all sequences are highlighted Red, disulphide bridges are indicated by bold broken dots. Helices in cloned IFNα-2b and IAS are indicated by alphabets (A,B,C,D,E,F,G) on the top of alignment and amino acids involved in helix are highlighted by Grey color.