Somatic molecular traits refer to the molecular aberrations that are observed in the cells of the body – aberrations that are not inherited but acquired over the course of life. These include changes in the protein coding sequence of DNA (that is, mutations) and changes in gene expression, copy number, and methylation. Each of these can be studied at the level of single genes or genome-wide biological pathways and signatures that reflect the cumulative effects of specific underlying mutagenic processes such as defects in DNA damage repair.

Somatic molecular aberrations are the key driver of the transformation of normal cells into tumour cells. Despite their profound mechanistic importance to the development of cancer, we do not really know how exogenous factors, such as our lifestyle and health-related behaviours, and endogenous factors, such as blood biochemistry, impact on somatic molecular traits. Over the course of ICEP2, we will use Mendelian randomisation to comprehensively study the influence of these factors on somatic traits.

This theme is chaired by Amy Francis.