MYD88^L265P MAF analysis in 163 patients with IgM monoclonal gammopathies. (A) MAF analysis of 105 tDNA samples and 144 cfDNA samples shows that the MYD88^L265P mutation fraction is higher in tDNA compared with cfDNA (P < .01). (B₁) Correlation analysis between BM infiltration of all patients and MAF in tDNA samples showed a moderate positive correlation. (B₂) Correlation analysis between BM infiltration of all patients and MAF in cfDNA samples showed a low positive correlation.