Cancer‐associated fibroblasts (CAFs) are one of the most abundant stromal components in the developing TME and are recognised by numerous markers such as fibroblast‐specific protein 1 (FSP1/S100A4), vimentin, α‐smooth‐muscle actin (αSMA), fibroblast activation protein (FAP), PDGF receptor‐α (PDGFR‐α) and podoplanin. The gene discussed is S100A4; the disease is cancer.