KRT18 (keratin 18) is a cytoskeletal protein that forms intermediate filaments essential for epithelial cell structure and function. KRT18 pairs with KRT8 to form filaments involved in actin stress fiber formation and cellular responses to mechanical stress 1. The protein plays critical roles in epithelial morphology, with KRT18 filament organization determining proper tubule elongation 1. KRT18 functions as a regulator of cell proliferation and apoptosis, modulating alternative splicing of genes in these pathways and promoting cell survival 2. In cancer contexts, KRT18 expression is frequently altered and serves as a prognostic biomarker, with high expression associated with poor outcomes in lung adenocarcinoma and squamous cell carcinoma 34. The protein can be targeted by microRNAs such as miR-186-3p, which suppresses colon cancer progression by inhibiting KRT18 and downstream MAPK signaling 5. KRT18 has emerged as a potential frailty biomarker in aging-related diseases 6 and shows promise as a therapeutic target in multiple cancer types. Its involvement in immune cell interactions and inflammatory responses further underscores its clinical relevance 7.