IDF Common Ground is a private social network and discussion forum exclusively for teens living with primary immunodeficiencies (PI), a group of more than 250 disorders in which part of the body’s immune system is missing or functions improperly. This online community from the Immune Deficiency Foundation (IDF), the national patient organization for persons with PI, gives teens with these rare, chronic disorders the opportunity to connect with teens in the PI community, ask questions, make suggestions, share their stories and inspire others.