Table 1.

Biological Markers Types and Examples in Clinical Application

Marker Type	Definition	Examples in Clinical application
Diagnostic marker	A biological marker is used to diagnose a specific disease or condition.	PSA (prostate-specific antigen) test for prostate cancer (Ilic et al., 2018)
Predictive marker	A biological marker helps predict how a disease will develop or how a patient will react to a certain treatment.	HER2 (human epidermal growth factor receptor 2) gene for breast cancer treatment (Zhang et al., 2020)
Prognostic marker	A biological marker helps predict the future outcome of a disease, such as the likelihood of survival or progression.	LDH (lactate dehydrogenase) levels for Hodgkin's lymphoma prognosis(Qi et al., 2021)