Recent evidence supports the diagnostic utility in employing a FC assay which captures and detects the presence of fusion proteins in leukemic cell lysates, such as the BCR-ABL1 protein in ALL [11] and PML-RARα protein in promyelocytic leukemia [16], where a rapid diagnosis is essential for patient management and treatment outcome [14]. The gene discussed is ABL1; the disease is acute promyelocytic leukemia.