Patients and ethics
All newly-onset pSS and SLE patients were enrolled in Peking Union Medical College Hospital (PUMCH) and met the 2016 ACR-EULAR classification[22] and the 1997 classification criteria of the American College of Rheumatology[23], respectively. Labial tissues were obtained from patients who underwent labial gland biopsy at the department of stomatology in PUMCH. Patients all signed informed consent for their residual tissues after the pathological examination. This study was approved by the Ethics Committee of PUMCH (No: K2525).