A biomarker, or Biological Marker, can be understood as a molecule that is present (or absent) from a particular cellular type. This facilitates the characterization of a cell type, their identification, and eventually their isolation.

A biomarker that identifies senescent human cells in culture and in aging skin in vivo.
Clinical and Biomarker Changes in Dominantly Inherited Alzheimer’s Disease
Protein biomarker discovery and validation: the long and uncertain path to clinical utility.
Cerebrospinal fluid biomarker signature in Alzheimer's disease neuroimaging initiative subjects ?
Inflammation in Atherosclerosis: From Vascular Biology to Biomarker Discovery and Risk Prediction
Diffusion-weighted magnetic resonance imaging as a cancer biomarker: consensus and recommendations
Biomarker analyses and final overall survival results from a phase III, randomized, open-label, first-line study of gefitinib versus...
Efficacy according to biomarker status of cetuximab plus FOLFOX-4 as first-line treatment for metastatic colorectal cancer: the OPUS...
Adiponectin – journey from an adipocyte secretory protein to biomarker of the metabolic syndrome
Bevacizumab in combination with chemotherapy as first-line therapy in advanced gastric cancer: a biomarker evaluation from the AVAGA...