Inclusion Criteria for controls (patients relatives and unrelated subjects):  Individuals aged<18 y/o. Individuals > 6 kg Individuals not affected by an immune-related disease or not affected by cancer Individuals whose parents have signed an enlightened consent.  Inclusion criteria for patients  Individuals with health insurance. Patients treated at Necker hospital with PIDs and autoimmunity/inflammation related to known genetic defects (cytopenia, Enteropathy Inflammatory bowel disease (IBD), Systemic Lupus Erythematosus (SLE), Juvenile Idiopathic Arthritis (JIA), Familial Hemophagocytic Lymphohistiocytosis (FHL), chronic EBV infection associated (Ca-EBV) with EBV-infected T and/or Natural Killer (NK) cells and with a high risk to develop macrophage activation syndrome similar to FHL. See table below for diagnosis inclusion criteria. Individuals aged<18 y/o. Individuals > 9 kg Patients whose parents have signed an enlightened consent.  Exclusion Criteria:  Intake of antibiotics within 2 weeks prior inclusion Absence of parent's or child consent form Cytotoxic cancer treatments antiviral treatments (HIV, hepatitis …) Short term life-threatening conditions Individuals placed under judicial protection