Describe the treatment of B-cell non-Hodgkin lymphoma patients who receive lenalidomide single drug or lenalidomide combined with rituximab (with or without other drugs), and evaluate the efficacy and safety of lenalidomide single drug or lenalidomide combined with rituximab (with or without other drugs) in the real-world setting.

This is a multi-center prospective, observational real-world study, targeting patients with B-cell non-Hodgkin's lymphomas. This study is designed to evaluate the efficacy and safety of lenalidomide single drug or lenalidomide combined with rituximab (with or without other drugs) in the real-world setting.

This study will mainly focus on the following three cohorts:

Cohort 1: patients diagnosed with CD20-positive diffuse large B-cell lymphoma; Cohort 2: patients diagnosed with CD20-positive follicle lymphoma; Cohort 3: patients on maintenance treatment who have achieved complete remission or partial remission after induction therapy.

Inclusion Criteria:

• Diagnosed as B-cell non-Hodgkin's lymphoma
• Voluntary participation in this study and the signing of an informed consent form
• The researchers assessed that the patient will benefit from the treatment of lenalidomide single drug or lenalidomide combined with rituximab (with or without other drugs)

Exclusion Criteria:

• Contradictions to any drug in the treatment regimen
• Pregnant or lactating women
• Patients who were not considered suitable for the study by the researchers

This study focus on patients diagnosed with B-cell non-Hodgkin's lymphoma and treated with lenalidomide single drug or lenalidomide combined with rituximab (with or without other drugs) in the real-world setting.