COL2A1 encodes type II collagen, the predominant collagen in cartilaginous tissues essential for skeletal development and function 1. Type II collagen comprises three identical alpha-1(II) chains and is the major collagen synthesized by chondrocytes, localized to articular cartilage, vitreous humor, inner ear, and nucleus pulposus 1. The protein confers tensile strength to the extracellular matrix and is critical for cartilage's ability to resist compressive forces during linear growth 2. Mutations in COL2A1 cause type II collagenopathies, a group of 16 definite autosomal dominant or recessive disorders with over 405 documented mutations 1. Stickler syndrome type 1, the most common COL2A1-associated condition, results from loss-of-function mutations causing nonsense-mediated decay in >90% of cases 3. Patients present with characteristic vitreous anomalies, retinal detachment, cleft palate, hearing loss, and arthropathy 4. Additional COL2A1-associated diseases include achondrogenesis 2, Kniest dysplasia, and multiple epiphyseal dysplasia variants. SOX-9 and the retrotransposon-derived factor RTL3 co-regulate COL2A1 expression in chondrocytes 5. In osteoarthritis, COL2A1 expression is reduced; enhancing GFPT1 with glutamine restores COL2A1 expression and cartilage anabolic metabolism 6. COL2A1 somatic alterations occur in 19.3% of chondrosarcomas and 31.7% of enchondromas, implicating the gene in cartilaginous tumor development 7.