CRLF2 and acute lymphoblastic leukemia: CRLF2 rearrangement (12 cases, 42.9% of Ph-like ALL): 7 cases (58.3%) were IGH-CRLF2 [t(14; 19)] confirmed by FISH (split signals in 15%–22% of cells) and RT-PCR (Ct 28.3 ± 3.1); 5 cases (41.7%) were P2RY8-CRLF2 (19p13.2 deletion) validated by FISH (colocalized signals in 12%–18% of cells) and WES (deletion breakpoint at chr19:10,234,567–10,238,912).