biomarkernoun [ C ]
uk/ˈbaɪ.əʊˌmɑː.kər//ˈbaɪ.oʊˌmɑːr.kɚ/specializedsomething, for example a gene or substance, that shows that a particular biological process or condition is present:
The Johns Hopkins team have identified a genetic change, or biomarker, that can be measured in the blood of colon cancer patients.