Historical clue formulations

• Immune response trigger — 2023-12-27
• Immune response trigger — 2018-01-24
• A or B in blood typing, e.g. — 2004-07-30
• Immunologist's concern — 2003-06-06
• Immunity trigger — 2003-04-26
• Immune response stimulus — 2000-09-23
• Cause of an immune response — 1999-08-01
• Body toxin — 1995-03-25