Suppose there are 10,000 genes in an experiment, only 50 (0.5%) of which play a known role in making cholesterol.

Aluminium has no known biological role in plants or animals.

She had a successful 50-year career on stage while taking some of her better known roles to film.

AAV is not considered to have any known role in disease.

Tin has no known natural biological role in living organisms.

This correlates with other known emotional roles of the insula.

Ruthenium, osmium, and hassium have no known role in the human body.

His last known role was as one of the pool hall men in the 1986 movie Wildcats.

Tungsten has no known biological role in the human body.

Erbium does not play any known biological role, but is thought to be able to stimulate metabolism.