JAK2 and acute lymphoblastic leukemia: While overall survival is comparable, event-free survival is significantly lower in patients with <i>ETV6::RUNX1</i>-like ALL, with NCI risk, early treatment response, <i>IKZF1</i> deletions, <i>CRLF2r,</i> and <i>JAK2</i> mutations having prognostic relevance.