ELOVL2 and breast cancer: There is no agreed definition and list of DNA methylation‐based measures of epigenetic ageing, and several studies have considered potentially valuable methylation‐based measures including ELOVL2 methylation, an individual CpG that is strongly correlated with age [26], stochastic epigenetic mutations, which were reported to be associated with a fairly strong increase in breast cancer risk [33], methylation‐based telomere length, which showed weak or null association with cancer risk [3, 8], and Zhang's mortality risk score, which is widely studied but weakly correlated with age [34].