Diagnostic and treatment saga of a 16-year-old with autoimmune cytopenias. Diagnostic evaluation and steps of managements are color-coded (hematology in red, infection in green, and specific immune defect in yellow). AB, antibody; ALPS, autoimmune lymphoproliferative disease; ct, count; DNT, double negative T cell; HD, high dose; IvIg, intravenous Ig; plt, platelet; RTx, replacement therapy.