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UKCRC Health Research Classification System

2.1 Biological and endogenous factors

Main inclusion criteria

Identification and characterisation of endogenous factors known or suspected to be involved in the cause, risk or development of disease, conditions or ill health including

  • genes and gene products, molecular, cellular and physiological structures and functions
  • biological factors linked to ethnicity, age, gender, pregnancy and body weight
  • endogenous biological factors or pathways involved in responses to infection or damage by external factors
  • metastases, degenerative processes, regeneration and repair
  • complications, reoccurrence and secondary conditions
  • bioinformatics and structural studies
  • development and characterisation of models


Advice on research activities

To be used to code all biological causes of disease including the following

  • Host cell biological responses to infection
  • prion/TSE aetiological studies
  • ischemic preconditioning

Characterisation of pathways to identify candidates that may potentially be used as diagnostic markers should be coded as 2.1 Endogenous risks and not 4.1 Marker discovery.

Characterisation of the biological cause of psychological conditions should be coded as 2.1. However 2.3 Psychological risks can also be used if the study includes investigation of symptoms and characteristics of the psychological condition.

Awards that are focused on therapeutic development or diagnostics will often yield information about the mechanism of a disease. However, this is generally a secondary outcome and shouldn’t be coded 2.1 unless this is clearly stated as one of the primary objective of the research.

Excludes basic immune and pain responses and wound healing studies that are not linked to a specific disease/condition stimulus and normal ageing or pregnancy not linked to a condition which should be coded as 1.1 Biological normal function.

Excludes normal cell cycle and normal DNA repair and replication which should be coded as 1.1 Biological.

Official terminology

Full name of code

Short name Unique ID
2.1 Biological and endogenous factors 2.1 Endogenous risks



Related external links

Common Scientific Outline (CSO) – 1.2 Cancer Initiation: Alterations in Chromosomes
Common Scientific Outline (CSO) – 1.3 Cancer Initiation: Oncogenes and Tumour Suppressor Genes
Common Scientific Outline (CSO) – 1.4 Cancer Progression and Metastasis
Common Scientific Outline (CSO) – 2.2 Endogenous Factors in the origin and cause of cancer
Common Scientific Outline (CSO) – 2.3 Interactions of Genes and/or Genetic Polymorphisms with Exogenous and/or Endogenous Factors