Table 1.

European Society for Medical Oncology (ESMO) clinical actionability of molecular targets

Tier I	Alteration-drug match is associated with improved outcome in clinical trials
Tier II	Alteration-drug match is associated with antitumor activity, but magnitude of benefit is unknown
Tier III	Alteration-drug match is suspected to improve outcome based on clinical trial data in other tumor types(s) or with similar molecular alteration
Tier IV	Preclinical evidence of actionability
Tier V	Alteration-drug match is associated with objective response, but without clinically meaningful benefit
Tier X	Lack of evidence for actionability