Inclusion Criteria:

          1. Histologically diagnosed non-Hodgkin's lymphoma, refractory or relapsed after 1st line
             treatment.

          2. Paraffin block of the lesions available for immunohistochemical analysis

          3. Candidate for ESHAP salvage therapy

          4. Evidence of at least one lesion with a diameter of 1.5 cm

          5. Age of over 20 years

          6. Eastern cooperative oncology group performance status (ECOG) less than or equal to 2.

          7. Adequate kidney function with serum creatinine< 2.5 mg/dL, creatinine clearance ≥ 50
             mL/min

          8. Adequate liver function with aspartate transaminase (AST)/alanine aminotransferase
             (ALT) lower than or equal to 3 times the normal upper limit; Total bilirubin lower
             than or equal to 1.5 times the upper limit ;alkaline phosphatase lower than or equal
             to 5 times the normal upper limit.

          9. Adequate bone marrow function with absolute neutrophil count ≥ 1,000/uL; platelets ≥
             75,000/uL; hemoglobin ≥ 9.0 g/dL

         10. Patients who gave voluntarily informed consent before performing any test test that is
             not part of routine care of patients

        Exclusion Criteria:

          1. Patients with history of exposure to imatinib or other Bcr-Abl tyrosine-kinase
             inhibitors

          2. Known or suspected hypersensitivity to imatinib

          3. Potential use or usage alteration of CYP3A4 inducers or inhibitors from prior to 21
             days of to the test regimen until the initiation of round 2 ESHAP. Exceptions are
             itraconazole and fluconazole for treatment or prevention of fungal infection,
             hydrocortisone and dexamethasone for treatment of nausea/vomiting/fluid retention, and
             methylprednisolone as a part of the ESHAP regimen.

          4. Known involvement of the central nervous system (CNS) by lymphoma.

          5. Pregnant or breast-feeding. Females of childbearing potential who do not agree to
             undergo pregnancy tests or repeated use effective birth control while included in the
             clinical trial.

          6. Serious or uncontrolled medical condition, such as presence of abnormal or clinically
             significant cardiac disease, such as acute myocardial infarction or unstable angina
             within 6 months prior to initiation of treatment with ESHAP-imatinib, serious
             neurological or psychological conditions such as dementia or epilepsy, or uncontrolled
             active infection.

          7. Prior history of malignancy other than to non-Hodgkin's lymphoma (except basal or
             squamous cell skin and in situ carcinoma of the cervix) unless the patient free of
             disease beyond 5 years are.

          8. HIV positive and in treatment.