Functional experiments showed that NAP1L1 overexpression promoted proliferation, migration, invasion, and clonogenicity in osteosarcoma cells.<h4>Conclusion</h4>This study delineates ICD-related transcriptional heterogeneity in osteosarcoma at single-cell resolution and establishes a robust ICD-based prognostic signature. The gene discussed is NAP1L1; the disease is osteosarcoma.