COL19A1 encodes type XIX collagen, a fibril-associated collagen with interrupted triple helices (FACIT) that serves as a cross-bridge between collagen fibrils and other extracellular matrix molecules 1. The protein contains five collagenous domains (COL1-COL5) interrupted by six non-collagenous domains (NC1-NC6), with the NC1 domain capable of releasing bioactive matricryptins with anti-tumor and anti-angiogenic properties 2. COL19A1 plays a critical role in esophageal smooth muscle development and function, where it colocalizes with α-smooth muscle actin and serves as a scaffold for muscle cell migration 3. Mutations in Col19a1 cause abnormal smooth-to-striated muscle transitions in the esophagus and reduced hepatocyte growth factor expression 3. The gene shows tissue-specific expression patterns, with higher levels during fetal development and maintained expression in skeletal muscle and brain neurons 2. Clinically, COL19A1 expression serves as a predictive biomarker for immunotherapy responsiveness in esophageal squamous cell carcinoma, with high expression associated with better treatment outcomes 4. Additionally, COL19A1 has been identified as a prognostic factor in thyroid carcinoma and as a potential biomarker for clopidogrel resistance in coronary heart disease patients 56.