SAAL1 (serum amyloid A like 1) is a nuclear protein that promotes synovial fibroblast proliferation in response to pro-inflammatory stimuli, particularly TNFα signaling 1. The gene functions by facilitating cell cycle progression through upregulation of CDK6 expression, allowing cells to enter S phase without triggering apoptosis 12. In rheumatoid arthritis, SAAL1 is highly expressed in hyperplastic inflamed synovium with expression levels correlating positively with synovial lining thickness 1. SAAL1 knockdown inhibits synovial fibroblast proliferation and delays collagen-induced arthritis progression in mice, suggesting therapeutic potential for RA and osteoarthritis 12. Beyond joint disease, SAAL1 functions as an oncogene overexpressed in multiple malignancies associated with poor prognosis 34. In lung adenocarcinoma specifically, SAAL1 overexpression promotes cancer cell proliferation through cyclin D1 and Bcl-2 pathways and correlates with shortened overall survival 4. SAAL1 expression also associates with tumor immunogenicity, correlating with immune checkpoint markers and improved immunotherapy response in bladder cancer 3. These findings establish SAAL1 as both a disease-relevant biomarker and potential therapeutic target across inflammatory and malignant conditions.