After the early usage of arsenic trioxide combinated with ATRA and vigorous supportive treatment to maintain PLT ≥30×10<sup>9</sup>/L and FIB >1500 mg/L, this patient was under MMR and HCR without any clinical symptoms or signs until now.<h4>Conclusion</h4>False negative reslults of RT-PCR analysis for <i>PML-RARA</i> are rare in APL and ider(17) is even more infrequent. The gene discussed is RARA; the disease is acute promyelocytic leukemia.