Distribution of within- and between-mouse variance components. The total variance (A) and estimated between-mouse (B) and within-mouse (C) variance components are shown as smoothed density histograms after square root transformation. The vertical bars (left panel of B) represent the percentage of probes with estimated variance components less than 1×10-4. These probes are not included in the density plot (right panel of B). Tissues are indicated by colour (Adipose: blue; Heart: red; Kidney: green; Liver: black).