A cohort of 19 JMML patients representing the four main subtypes (8 PTPN11, 5 KRAS, 4 NRAS, and 2 NF1 samples;Supplementary Table 1) was analyzed together with 3 age-matched healthy donors (HD; GEO ID: GSE147523) to study circRNA expression in patients with JMML. This evidence concerns the gene NF1 and juvenile myelomonocytic leukemia.