Clinical Research Directory

Inclusion Criteria: (1) Screening stage 1. Over 30 years old. 2. Volunteer to participate in this study and sign an informed consent form. (2) Follow up stage 1. According to previous studies, a positive rate of 5% -8% was found in subjects with positive M protein screening. Each sub center included approximately 50-80 positive subjects based on actual conditions. At the same time, control subjects with negative M protein testing were matched by age and gender parameter 1:1. 2. Volunteer to participate in the follow-up phase of the study and sign an informed consent form. Exclusion Criteria: (1) Screening stage 1\) Previously diagnosed with hematological diseases such as plasma cell or other B lymphocyte proliferative diseases. Culling criteria: 1. Samples with incomplete or untraceable subject data. 2. Unqualified samples: including serum samples with severe hemolysis, fatty blood or jaundice, insufficient sample, and samples not stored as required. 3. The subject requested to withdraw from the study midway. 4. Duplicate samples of subjects at the same time point.