The features of samples including gender, disease duration, xerostomia, saprodontia, anti-Ro/SSA, ANA, ANA and RF double positive, and anti-Ro52, which have been demonstrated to relate to pSS (Table 1), were enrolled in multiple logistic regression, together with IHC scores of subcellular EpCAM. The gene discussed is TRIM21; the disease is xerostomia.