Germline mutations in CBL in patients with JMML are predominantly located in intron 7 and exons 8 and 9 (linker and RING finger domain); chromosome 11q isodisomy, also known as copy-neutral loss of heterozygosity (CN-LOH), was reported as the most frequent mechanism resulting in the homozygous state of CBL mutations with no other secondary genetic abnormalities [38,39,40]. This evidence concerns the gene CBL and juvenile myelomonocytic leukemia.