JAK2 and acute lymphoblastic leukemia: Finally, Auer et al reported a first intriguing example of a “double-hit one-pathway” scenario, in which the biparental inherited combination of two rare germline variants, JAK2 (G571S) and STAT3 (K370R), whose products synergistically interact in the same disease-relevant JAK/STAT signal transduction pathway, is obviously sufficient to induce a Ph-like BCP-ALL (49).