TGF-β1, through canonical SMAD2/3 signaling, induces a myofibroblast-like phenotype characterized by high expression of fibrillar collagens such as COL1A1, COL3A1, and COL11A1 [53,54,55,56], promoting desmoplasia and matrix stiffening in gastric cancer, which are predictive of poor prognosis and enriched in CAF-high tumors [57]. Here, COL1A1 is linked to gastric cancer.