The methylation levels at sites HSD9-2, HSD9-3, HSD23-2 and HSD23-3 of HSD promoter were significantly lower in preeclampsia than in normal pregnancy (P = 0.002, 0.031, 0.047 and 0.001, respectively) (Figure 1), but the methylation levels at site HSD9-1 and HSD23-1 did not significantly differ (P = 0.279 and 0.789, respectively, Table 2) (Figure 2). Here, CHST3 is linked to preeclampsia.