text: When quality control of TEMPs is considered, a risk assessment needs to be conducted. A risk is defined as a "potentially unfavourable effect that can be attributed to the clinical use of advanced therapy medicinal products (ATMPs) and is of concern to the patient and/or to other populations (e.g. caregivers and off-spring)". Some risks include immunogenicity, disease transmission, tumor formation, treatment failure, undesirable tissue formation, and inadvertent germ transduction. A risk factor is defined as a "qualitative or quantitative characteristic that contributes to a specific risk following handling and/or administration of an ATMP". The integration of all available information on risks and risk factors is called risk profiling. Due to the fact that every TEMP is different, the risks associated with each one of them vary and, subsequently, the procedures that must be implemented to ensure its quality are also unique to the product. Once the risks associated with the TEMP are identified, the appropriate tests must be developed and validated accordingly. Thus, there is no standard set of tests for the quality control of TEMPs. The EMA has released a set of regulatory guidelines on the topics to be considered by companies involved in the development and marketing of medicines for use in the European Union. These guidelines have to be followed in order for the marketing authorization of a product to be issued. Fictitious examples of risk analysis for further elucidation of the process are provided in the EMA guidelines.