Enter a clue or pattern or both:
The Clue
Foreign instigators? (8 letter answer)
The Answer
ANTIGENS
Tags
Notes
The answer ANTIGENS is so rare that it appears less than once every 2500 puzzles.
Definition
ANTIGEN as a noun:
1. any substance (as a toxin or enzyme) that stimulates an immune response in the body (especially the production of antibodies)