This is a non-intervention, prospective, open-label and observational clinical trial. The researchers plan to recruit at least 50 qualified patients. The main purpose of this study was to establish a population pharmacokinetic(PPK) model of lenalidomide and explore factors associated with the adverse events of lenalidomide from a pharmacokinetic(PK) perspective.

Studies have found that there is significant interpatient variability in the plasma concentration of lenalidomide, and the PK parameters of lenalidomide do not affect its efficacy but may be correlated with its toxicity. Therefore, the investigators plan to conduct a PPK study on lenalidomide to identify factors contributing to interpatient PK differences, thus refining regimens to mitigate its adverse reactions, in the hope of optimizing the clinical application of lenalidomide. At least 50 patients are planned to be included. It should be noted that the study does not interfere with the patients' treatment plans. Except for the discomfort during blood sampling, patients will not be exposed to any risks.

Inclusion Criteria:

• Patients who are above the age of 18
• Patients who receive lenalidomide treatment

Exclusion Criteria:

• Patients have received other investigational systemic drugs
• The clinical data are deemed insufficient
• There appear other factors that rendered them ineligible.

Patients with different diagnosis are eligible if they were above the age of 18 and received lenalidomide treatment.