Why is the H1N1 Virus Called Swine Flu?

The H1N1 virus is called the "Swine Flu" virus because rigorous lab test stated that most of the genes in this virus are closely alike to influenza viruses that usually only occurs in pigs or boars in the USA. Further studies show that it is very different from the what normally passes through USA pigs. It consists of two genes that generally come from the European and Asian pigs. Its made up of avian genes and human genes.