CD19 and acute myeloid leukemia: Pertinent markers, such as HLA-DR and CD34 (negative) in acute promyelocytic leukaemia (APL), CD19 and CD56 in AML with maturation and AML with RUNX1::RUNX1T1 fusion, and CD2, CD15, and CD34 in myelomonocytic AML with abnormal eosinophils, provide insights essential for precise subclassification and informed clinical management [1].