This study is to explore the efficacy and safety of tofacitinib combined with chidamide in patients with relapsed and refractory extranodal NK/T cell lymphoma.

Inclusion Criteria:

• 1. Patients with primary refractory or recurrent extranodal NK/T cell lymphoma that do not qualify for treatment protocols of higher priority.

  2. Adequate renal function, as defined by estimated serum creatinine clearance >/=50 ml/min and/or serum creatinine </= 1.8 mg/dL.

  3. Adequate hepatic function, as defined by serum glutamate oxaloacetate transaminase (SGOT) and/or serum glutamate pyruvate transaminase (SGPT) </= 3 x upper limit of normal; serum bilirubin and alkaline phosphatase </= 2 x upper limit of normal.

  4.. Adequate cardiac function with left ventricular ejection fraction >/= 50%. No uncontrolled arrhythmias or symptomatic cardiac disease.

  5. Performance status 0-1. 6. Negative Beta diffusing capacity of lung for carbon monoxide (HCG) text in a woman with child-bearing potential, defined as not post-menopausal for 12 months or no previous surgical sterilization

Exclusion Criteria:

-1. Patients relapsed after allogeneic stem cell transplant 2. Patients with active hepatitis B or C(HBV DNA >/=10,000 copies/mL). 3. Active infection requiring parenteral antibiotics 4. HIV infection, unless the patient is receiving effective antiretroviral therapy with undetectable viral load and normal cluster of differentiation 4 (CD4) counts 5. Evidence of either cirrhosis or stage 3-4 liver fibrosis in patients with chronic hepatitis C or positive hepatitis C serology.

6. Patients with a cQT longer than 500 ms