[4] Prusiner discovered prions, a class of infectious self-reproducing pathogens primarily or solely composed of protein, a scientific theory considered by many as a heretical idea when first proposed.

He spent his childhood in Des Moines and Cincinnati, Ohio, where he attended Walnut Hills High School, where he was known as "the little genius" for his groundbreaking work on a repellent for Boxelder bugs.

Later Prusiner moved to the National Institutes of Health, where he studied glutaminases in E. coli in the laboratory of Earl Stadtman.

Prusiner and his co-workers suggested "One scientific theory, viewed as heretical in that it seems to challenge the role of nucleic acids as the exclusive carriers of genetic information."

[3] In this work, he coined the term prion, which comes from the words "proteinaceous" and "infectious," in 1982 to refer to a previously undescribed form of infection due to protein misfolding.