Autoimmune disease is the result of the body's immune system targeting and attacking its own tissues in the same way that it would normally tackle infection. The tissues affected become inflamed and damaged.
The city of Venice is a major center of culture and tourism in Italy, a country in southeastern Europe. It is famous for its beautiful canals, palaces, and art. The city is built on more than 100 small islands.
The Italian city of Venice (pictured) is renowned for its floods that can bring it to a standstill. A group of people sit at a table in a flooded St Mark's Square in Venice in 2012. Individual blocks of the flood defence system, pictured from inside the lagoon, are fully raised.