XY scatterplots show the overall methylation differences between and within cell types. (A) 2 MGUS samples are very similar. (B) A myeloma sample shows hypomethylation of probes compared with an MGUS sample. (C) Two myeloma samples show heterogeneity of methylation. (D) A PCL sample shows hypermethylation compared with a myeloma sample. (E) 2 PCL samples have equally heterogeneous methylation profiles. (F) Summary of R² correlation values of samples within each cell type.