Overreactions, friendly fire, and your immune system betraying you on boards.
Types I-IV, IgE vs IgG vs T-cells, timing, classic diseases, board traps. Drag-drop type sorter + elimination game + 12-question pool.
The Big 10: Bruton's, SCID, DiGeorge, CGD, Wiskott-Aldrich, CVID, Hyper-IgM, Chediak-Higashi, IgA deficiency, complement. Disease cards, drag-drop sorting, decision tree, elimination game + 14-question pool.