heterogeneity. Importantly, even within a sample of lymphocytes, each cell type (e.g., B cell, T cell, NK cell) will have a unique epigenomic profile and heterogeneity in the relative cell proportions between individuals can lead to spurious results. Cellular heterogeneity is frequently corrected using the approach of Houseman and colleagues (Houseman et al., 2012). After correction and normalization, a quantitative metric representing percent methylation can be used as a dependent or independent variable in subsequent analysis.
