The term "ATM" is understood to refer to both advanced therapy medicinal products that have obtained a marketing authorization and advanced therapy medicinal products that are the subject of clinical trials or are used as a reference in a clinical trial (investigational advanced therapy medicinal product). If specific provisions only concern advanced therapy medicinal products that have obtained a marketing authorization, the term used is "authorized ATM". If specific provisions only concern investigational advanced therapy medicinal products, the term used is "investigational ATM". Nothing in this guide (including the risk-based approach) can be considered as constituting a derogation from the terms of the marketing authorization or the clinical trial authorization.