Figure 1. XCI-skewing in SLE and controls The correlation between XCI (y-axis) and age (x-axis) is shown in panels on the left and the proportions of individuals (y-axis) with random (50%–79%), skewed (80%–89%) and extremely skewed (>90%) XCI across increasing age groups (x-axis) are shown in panels on the right. Controls (n=796) are in the upper panels and SLE cases (n=181) are in the lower panels. SLE, systemic lupus erythematosus; XCI, X chromosome inactivation.