The RadoNorm course CELET (Cellular and genotoxic effects of high and low LET ionising radiation introduction to radiation biology) will be organised this year again and held in Stockholm University from 13th to 24th November 2023. The aim of the course is to acquaint students with techniques of studying genotoxic effects of ionising radiation which are of relevance for RadoNorm and the broad field of radiation research. The course targets students and young researchers with various backgrounds who want to get a basic introduction to biological effects of radiation. More information can be found in the flyer https://www.radonorm.eu/wp-content/uploads/2023/09/CELET-2023-flyer.pdf. Deadline for applications is 30th September 2023.