<human>:  What is the function of the thymus?
<bot>: The thymus is a gland in the chest that is responsible for the development of the immune system. It is located in the upper left part of the chest, behind the breastbone. The thymus is made up of two lobes, the right and left, and is responsible for producing T-cells, which are a type of white blood cell that helps the body fight off infections.