In this prospective, single arm, open label, clinical trial, a total of 50 acute leukemia of ambiguous lineage patients will be enrolled. Patients will receive acute lymphoblastic leukemia (ALL) -based chemotherapy and are permitted to receive allogeneic hematopoietic stem cell transplantation (HSCT) after CR . Otherwise, they will finish the consolidation chemotherapy. Patients with t(9;22) will receive chemotherapy combined with tyrosine kinase inhibitors. The purpose of current study is to evaluate the clinical efficacy of ALL-based chemotherapy，effect of genetic abnormality and minimal residual disease (MRD) on prognosis in patients with acute leukemia of ambiguous lineage.

Inclusion Criteria:

1. Patients aged above 14 years with acute leukemia of ambiguous lineage .
2. Eastern Cooperative Oncology Group (ECOG) Performance status 2.
3. Adequate end organ function as defined by: Total bilirubin ≤ 1.5 x upper limit of normal (ULN); serum glutamic-oxaloacetic transaminase(SGOT) and serum glutamic pyruvic transaminase(SGPT) ≤ 2.5 x ULN; Creatinine ≤ 1.5 x ULN; Serum amylase and lipase ≤ 1.5 x ULN; Alkaline phosphatase ≤ 2.5 x ULN unless considered tumor related; Patients must have adequate cardiac function (ejection fraction ≥ 45 % on Multiple Gated Acquisition (MUGA) scan).
4. Patients must have the following laboratory values (≥ lower limit of normal (LLN) or corrected to within normal limits with supplements prior to the first dose of study medication.): Potassium ≥ LLN; Magnesium ≥ LLN; Phosphorus ≥ LLN
5. Patients should sign informed consent form.

Exclusion Criteria:

1. Impaired cardiac function:

   Long QT syndrome or a known family history of long QT syndrome; clinically significant resting brachycardia (<50 beats per minute); ejection fraction < 45 % on MUGA scan. Corrected QT (QTc) interval > 450 msec on baseline ECG (using the QTcF formula). If QTcF interval>450 msec and electrolytes are not within normal ranges, electrolytes should be corrected and then the patient re-screened for QTc. Myocardial infarction within 12 months prior to starting study; other clinically significant heart disease (e.g. unstable angina, congestive heart failure or uncontrolled hypertension, uncontrolled arrhythmias).

2. Other concurrent severe and/or uncontrolled medical conditions:

   Patients with another primary malignant disease, except those that do not currently require treatment; acute or chronic liver, pancreatic or severe renal disease; another severe and/or life-threatening medical disease.

3. Patients who are: (a) pregnant and (b) breast feeding.