SNRPC (small nuclear ribonucleoprotein polypeptide C) is a core component of the U1 snRNP complex essential for pre-mRNA splicing. It directly recognizes the 5' splice site and stabilizes base-pairing between U1 snRNA and pre-mRNA, promoting early spliceosome assembly for both constitutive and alternative splicing 1. Beyond its canonical splicing role, SNRPC functions as an m6A RNA methylation regulator 2. Clinically, SNRPC dysregulation associates with multiple malignancies. In triple-negative breast cancer, SNRPC upregulation correlates with poor prognosis and promotes oncogenic transcription of genes like TNFAIP2, E2F2, and CDK4 via RNA Pol II enrichment; SNRPC ablation impairs cancer cell proliferation and invasion 1. Similarly, SNRPC overexpression in hepatocellular carcinoma correlates with advanced stage, poor survival, and epithelial-mesenchymal transition; high SNRPC expression associates with reduced immune infiltration and lower immunotherapy sensitivity 32. In ovarian cancer, SNRPC functions within networks associated with platinum chemotherapy resistance 4. Beyond malignancy, anti-SNRPC autoantibodies emerge as biomarkers for Ro/SSA-negative Sjögren's disease diagnosis, achieving 46% sensitivity and 95% specificity in multimarker panels 56. Genome-wide studies identify SNRPC variants associated with cardiovascular disease risk in Sjögren's disease patients and body weight regulation 78, suggesting broader immunological and metabolic functions beyond splicing.