PTPRC and Miyoshi myopathy: To investigate the characteristics of endothelial cell populations in MM patients and healthy controls, we utilized four scRNAseq datasets from de Jong et al. [5], merging scRNA-seq datasets from CD45− cells, CD45+ CD38+ cells (non-PC), CD45+ CD38− cells, and CD45+ CD38+ MM plasma cells (Figure 1A; cluster annotations were preserved from the original study (Figure S1)).