CRLF2 and acute lymphoblastic leukemia: Notably, in this study, we observed a high incidence (10.5%) of iAMP21, compared with reports from other ALL populations (1–2%) [24]; this disparity could influence the increased frequency of P2RY8::CRLF2 as a secondary abnormality, especially when it is detected in a low number of cells and does not result in a CRLF2 overexpression [24,25,26].