You don't turn him in because he's a research subject.
It has been the subject of much study, research and development ever since.
To that end, this model has been the subject of research for several scientists.
But the patients are, in fact, research subjects, he said.
The text is available online and has been the subject of research.
And they want to be cared for as patients, not research subjects.
Human performance in decision making terms has been the subject of active research from several perspectives.
Would that have occurred to her as a research subject before she met Tim?
This area is the subject of research in real and wind tunnel conditions.
Their relative importance has been the subject of much research and debate.