Finally, several of these deficiencies are associated with very unique features, independently of the high risk to develop EBV-driven lymphoproliferations, helping to the diagnosis, such as autoimmunity, inflammatory bowel disease (IBD), lung involvement, and neurological disorders that develop in RASGRP1, XIAP-, ITK-, and CORO1A-deficiency, respectively (Table 1). The gene discussed is RASGRP1; the disease is inflammatory bowel disease.