The phrase "are present in virtually" is correct and usable in written English.
It can be used to indicate that something exists or is found in almost all instances or situations being discussed.
Example: "These species are present in virtually every ecosystem on the planet."
Alternatives: "are found in nearly" or "exist in almost".
Prostaglandins, hormonelike substances that are present in virtually all tissues and body fluids, inhibit the secretion of hydrochloric acid.
These membrane proteins are present in virtually all mammalian tissues and regulate a large variety of responses in physio- and pathological conditions.
Together with their underlings, who are dubbed middlemen, they are present in virtually every defence deal though they are not allowed to visit the Ministry of Defence (MOD) or meet officials.
Composed of DNA sequences with no fixed address, these traveling salesmen of the genome are present in virtually all organisms and contribute to both genome structure and function.
We know that ATP binding cassette (ABC) transporters are present in virtually every cell and they play a central role in physiology.
The clay minerals are present in virtually all sandstone reservoirs, but the mineralogy, texture and distribution varies widely and affect both the production characteristics of the reservoirs and the wire-line log responses [1, 2].
Today the concept is present in virtually every body of law.
CD20 is present in virtually all patients with LPHL, and in a significant minority of patients with cHL.
Though Wiseman is never seen or heard, he's present in virtually every frame by the force of his analytical conception of the events onscreen.
The 42-year-old claymation artist's unique homemade-looking style is present in virtually any shot of any of his creations from any of his films.
Although taboos are often associated with the Polynesian cultures of the South Pacific, they have proved to be present in virtually all societies past and present.
