Quantitative analysis of repetitive-element methylation in malignant melanoma (MM). (A) Results of quantitative methylation analysis of the indicated repetitive elements in normal plasma cells (NPC; n = 4), monoclonal gammopathy of undetermined significance (MGUS; n = 7) and MM (n = 74). *P < 0.05, **P < 0.01 and ***P<0.001. (B) Scatter plots for correlating percentage long interspersed nuclear element-1 (LINE-1) methylation levels with those of the indicated repetitive elements. Pearson's correlation coefficients with regression lines and their 95% confidence intervals are shown on the plots.