Inclusion Criteria:  Group of Type 2 diabetes patients:  age 18 ~ 75 years old; type 2 diabetes patients diagnosed in the First Affiliated Hospital of Shandong First Medical University (Qianfoshan Hospital of Shandong Province) , HBA1C ≥7.0% and <10.5% ; patients signed informed consent.  Group of Thyroid Cancer patients:  age 18 ~ 75 years old; thyroid cancer patients diagnosed in the First Affiliated Hospital of Shandong First Medical University (Qianfoshan Hospital of Shandong Province) ; patients who signed the informed consent form.  Control Group:  age 18 ~ 75 years old; healthy population recruited from the First Affiliated Hospital of Shandong First Medical University (Qianfoshan Hospital of Shandong Province) ; living in the monitoring area for more than 6 months within 12 months; normal thyroid function and no history of thyroid cancer were needed in the control group; Fasting Blood Glucose level of 0.7 mmol/l was needed in the Control Group of Type 2 diabetes Mellitus Without History of diabetes; patients with informed consent.  Exclusion Criteria:  Group of Type 2 diabetes:  (1) pregnant, lactating women, patients with acute cardiac cerebrovascular disease; (2) patients with severe liver and Renal Impairment (related laboratory tests more than 2 times the normal) ; (3) patients with Type 1 diabetes; (4) participants in other clinical trials within 3 months; (5) patients with malignant tumors. (6) has the disease and so on serious anemia, is not suitable to carry on the patient which the blood draws the test.  Group of Thyroid Cancer:  patients with serious heart, liver and Kidney Diseases (related laboratory tests more than 2 times normal) ; patients with other malignant tumors.  Control Group:  patients with serious heart, liver or kidney disease; patients with iodine or Thyroid hormone; patients with confirmed malignant tumor; pregnant women or those who have recently taken contraception or estrogen.