This illustration depicted a 3D computer-generated rendering of a half-sliced influenza (flu) virus with a grey surface membrane, set against a black background. The virus’ surface proteins, hemagglutinin (HA) and neuraminidase (NA), were highlighted in light and dark blue, respectively. HA is a trimer, which is comprised of three subunits, while NA is a tetramer, which is comprised of four subunits, with a head region resembling a 4-leaf clover. Inside the virus, its ribonucleoproteins (RNPs) were shown, with their coiled structures, and three-bulbed polymerase complex on the ends. An influenza virus’ RNP is composed of both, RNA and protein. Every influenza virus has eight RNP segments, corresponding to the virus’ eight total gene segments. Three of these RNP segments, encode the virus’ surface proteins, i.e., the HA, NA and M proteins.