assesses toxicity of https://orcid.org/0000-0001-5809-9523 A relationship between a biomarker 'b' and an exposure agent 'e', where 'b' is used to indicate the likelihood, presence, or extent of toxicity as an adverse effect of exposure to 'e'. Clarification: An 'exposure agent' can be either a medical product or some substance (e.g., pesticide) , physical factor (e.g., radiation), or organism (e.g., virus) that originates from the environment. Basis: This relation is based on the 'BEST' classification of and definition for 'biomarker', as given by the FDA-NIH Biomarker Working Group: A defined characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or biological responses to an exposure or intervention, including therapeutic interventions. The BEST classification includes diagnostic, prognostic, susceptibility/risk, monitoring, predictive, safety, and pharmacodynamic/response biomarkers. See PMID:29405771 for details. Note that any given biomarker can be of a different type in different contexts. As an indicator of kidney issues, reduced creatinine clearance capability assesses_toxicity_of certain drugs (such as antibiotics or chemotherapy agents) to the kidneys. indicates clinical effect of Darren A. Natale