Cancer is a leading cause of morbidity and mortality worldwide. Its burden is expected to increase in the coming years as populations age and increase their exposure to unhealthy lifestyle factors. Most research on cancer aetiology has been conducted in adult populations. This has led to the identification of well-established risk factors in adulthood, such as smoking and obesity. Nevertheless, it is still unclear whether cancer risk may be influenced by early life exposures. Furthermore, the mechanisms by which early life exposures may influence cancer risk have not been fully elucidated. They possibly involve inflammation, changes in the microbiome, metabolism, insulin resistance, hormonal factors and epigenetic modifications. Therefore, the aim of this project will be to identify novel early life risk factors and molecular markers for the prevention of cancer.