Assertion: adenosine's effect | /r/HasProperty | direct one
Facets:
Source sentences:
text: However, whether the antitumor effect of Reishi is a direct one or is mediated via the immune system is not clear.
text: Adenosine exerts a direct depressant effect on the SA and AV nodes and may cause first-, second- or third-degree AV block, or sinus bradycardia.