The prognostic and immune significance of fibronectin type III domain-containing 1 gene in pan-cancer and its relationship with proliferation and migration of stomach adenocarcinoma

Abstract Background: Fibronectin type III domain containing 1 (FNDC1) exhibits emerging roles in tumorigenesis, yet its pan-cancer implications and mechanistic contributions to stomach adenocarcinoma (STAD) remain underexplored. This study systematically evaluates FNDC1’s prognostic relevance, immune interactions, and functional impact in STAD. Methods: Multi-omics analyses integrated FNDC1 expression, mutation profiles, and immune associations across 33 cancers using The Cancer Genome Atlas (TCGA) data. Immunohistochemistry assessed FNDC1, mismatch repair (MMR) protein, and human epidermal growth factor receptor 2 (HER2), and clinicopathological information