NPM1 and B-cell chronic lymphocytic leukemia: Analysis of allelic frequencies of mutations in regard to BCR clonality revealed that some somatic mutations are likely confined to distinct BCR-specific subclones (e.g., mutated 5′UTR of Hjurp in Q76 or 3′UTR of Npm1 in C25), while most of the mutations are subclonal within the major BCR-specific CLL clone (Fig. 5d, e).