A biologic is a catch all term for the created in the lab monoclonal antibodies and the like against specific things the body produces. They have them for all sorts of disease at present. Actemra is just one of many and it is specific for interlukine 6 which is a cytokine that is produced by the T cells in our immune system. It is one of many cells that produce an inflamatory respnse, which can be a good thing for a short time fighting an invader. (Virus etc) It is not a good thing when it goes on for awhile and starts a problem with healthy tissue. This is what autoimmune diseases are all about. So you want to find a way to calm the immune system and turn off these unwanted inflamatory responses. Easier said than done.