Overall, mutations affecting the CBL gene in myeloid malignancies show a predominance of deletions involving the exon 8 of this gene [107] at frequencies that vary from 15% of patients diagnosed with juvenile myelomonocytic leukaemia, to 13% of CMML (mostly the CBL Y371 mutation) [108,109], 10% of AML and 8% of atypical chronic myeloid leukaemia cases [109,110,111]. This evidence concerns the gene CBL and chronic myelomonocytic leukemia.