Inclusion Criteria:  Voluntarily participate in the clinical study and sign the informed consent; All OPLL patients meet the diagnostic criteria set out in the JOA Clinical Practice Guidelines for Spinal Ligament Osification 2019; Age ≥18, gender unlimited; All non-OPLL patients and healthy volunteers have no serious diseases of the heart, lung, brain, liver, kidney and blood system, such as autoimmune diseases, tumors, psychosis, infectious diseases, etc., and have no bad habits or recent history of taking special drugs.  Exclusion Criteria:  Unable to sign the informed consent; Patients who do not meet the inclusion criteria or diagnostic criteria; <18 years old; Women planning to become pregnant/lactating/pregnant; Complicated with serious heart, lung, brain, liver, kidney, blood system diseases, such as autoimmune diseases, tumors, mental illness, infectious diseases, drug addiction and other bad addicts;Those who have recently taken special drugs; Individuals who do not agree to donate peripheral blood or who are obviously uncomfortable with drawing blood.