NTRK1 and cancer: The activation of fibroblasts in many cancers is dependent on different paracrine cues such as growth factors and cytokines, e.g., fibroblast growth factor (FGF), transforming growth factor-β (TGFβ), platelet-derived growth factor (PDGF), receptor tyrosine kinase signalling, tumor necrosis factor, or reactive oxygen species, released by cancer cells and the infiltrating immune cells (Zhou et al., 2022) (Figure 2).