IGF1R (insulin-like growth factor 1 receptor) is a receptor tyrosine kinase that plays critical roles in cellular growth, metabolism, and disease progression. The receptor binds insulin-like growth factors and can form hybrid receptors with the insulin receptor (INSR), with binding specificity varying depending on the INSR isoform involved 1. IGF1R exhibits protein tyrosine kinase activity and activates downstream signaling pathways including PI3K-AKT cascades 2. In disease contexts, IGF1R demonstrates significant pathological relevance across multiple cancer types. In oesophageal squamous cell carcinoma, IGF1R upregulation under hypoxic conditions promotes cisplatin resistance by enhancing arginine and proline metabolism through c-MYC-mediated transcriptional activation 3. The receptor is highly correlated with drug resistance markers like ABCG2 in osteosarcoma 4 and serves as a therapeutic target in succinate dehydrogenase-deficient gastrointestinal stromal tumors, where IGF1R overexpression occurs due to hypoxia-inducible factor 1α upregulation 5. IGF1R also contributes to liver fibrosis through paracrine signaling mechanisms 2 and supports neuronal function in astrocytes, with IGF1R loss impairing mitochondrial complex I activity 6. Clinically, IGF1R represents a promising therapeutic target, with inhibitors like linsitinib showing synergistic effects with conventional chemotherapy 3.