Cancer is classically conceived as a genetic disease caused by somatic mutations acquired during life. In the last years, this has fuelled research efforts into the characterization of activating mutations in different tumour types. However, apart from knowing the activating mutation, other factors are also important in the development and optimization of an effective personalised treatment. During the 25th annual Belgian Society of Medical Oncology (BSMO) meeting 2023, Dr. Luc Dirix (GZA hospital, Belgium) discussed the significance of somatic mutations in normal tissues and their effect on cancer, with a special focus on clonal haematopoiesis of indeterminate potential (CHIP). Additionally, Dr. Dirix addressed the topic of cellular plasticity, which plays a fundamental role in cancer development.