1. Institute of Pediatric Hematology and Oncology Hospices Civils de Lyon, Claude Bernard Lyon I University Lyon France
2. Anatomy‐Cytology‐Pathology Department, Women‐Mother and Child Hospital Hospices Civils de Lyon Lyon France
3. Anatomy‐Pathology Unit Lyon Sud Hospital, Hospices Civils de Lyon, Claude Bernard Lyon I University Lyon France
4. Institute of Pediatric Hematology and Oncology Center Léon Bernard Lyon France
5. Laboratory of Lymphocyte Activation and Susceptibility to EBV INSERM UMR 1163‐Imagine Institute Paris France
6. Virology Laboratory, Infectious Agent Institute Croix‐Rousse Hospital, Hospices Civils de Lyon, Claude Bernard Lyon I University, Virpath, CIRI, INSERM U1111, CNRS 5308, ENS Lyon Lyon France