Due to the genetics of some types of Ph + ALL, the results of RT-qPCR and NGS/RQ-PCR lack agreement; this is usually demonstrated by a positive RT-qPCR for BCR/ABL1 fusion protein but negative clonal VDJ rearrangement (by NGS and/or RQ-PCR) [34]. The gene discussed is ABL1; the disease is acute lymphoblastic leukemia.