Eosinophilia is often associated with B-ALL with IGH::IL3 fusion [according to the World Health Organization (WHO) nomenclature 2022] or B-ALL with t(5;14)(q31.1;q32.3)/IL3::IGH [in accordance with the International Consensus Classification (ICC) 2022] [40]. The gene discussed is IL3; the disease is Increased total eosinophil count.