A non-randomized phase II clinical trial (NCT02723994) of the Children’s Oncology Group (COG) is currently underway, which is investigating the efficiency and safety profile of ruxolitinib in children, adolescents, and young adults aged 1–21 with newly diagnosed B-ALL with CRLF2 and JAK2 pathway alterations [53]. This evidence concerns the gene CRLF2 and acute lymphoblastic leukemia.