TGFB1 and cancer: Cancer‐associated fibroblasts (CAFs) arise from normal fibroblasts in response to various tumor microenvironmental signals, including cytokines such as TGF‐β and IL‐6, paracrine factors like PDGFs, Notch signaling, extracellular vesicles, as well as aging, inflammation, hypoxia, oxidative stress, and increased extracellular matrix (ECM) stiffness.