Characteristics of circulating biomarker DNA methylation profiles in MM. (A) Absolute number of CGIs that are assigned to a methylation level category as indicated by the color code in the right-side legend. Dark red indicates a highly methylated state (>80%), whereas the lightest color indicates the lowest methylation state (<20%). For BM-DNA, PBMNC-DNA, CTC-DNA, and cfDNA, each bar represents 1 patient with MM (n = 11). For control gDNA and control cfDNA, each bar represents 1 healthy individual (n = 4). (B) Principal component analysis of the methylation data from patient and control DNA samples. Control gDNA samples are indicated with red squares and control cfDNA samples with red triangles. For samples from patients with MM, BM-DNA samples are depicted as blue diamonds, PBMNC-DNA samples as blue squares, cfDNA samples as blue triangles, and CTC-DNA samples with a blue asterisk.