Loss of Heterozygosity and Mutations in the RAS-ERK Pathway Genes in Tumor Cells of Various Loci in Multiple Myeloma.

Multiple myeloma (MM) is a disease characterized by spatiotemporal heterogeneity of tumor clones. Different genetic aberrations can be observed simultaneously in tumor cells from different loci, and as the disease progresses, new subclones may appear. The role of liquid biopsy, which is based on the analysis of tumor DNA circulating in the blood plasma, continues to be explored in MM.