Indeed, current several phase I–II clinical trials are now testing the efficacy of Ruxolitinib in combination with chemotherapy in pediatric patients with activation of JAK/STAT signaling, including de novo high-risk CRLF2-rearranged and/or JAK pathway-mutant ALL or Ph-like ALL (NCT02723994, NCT02420717, NCT03117751). This evidence concerns the gene CRLF2 and acute lymphoblastic leukemia.