PI16 and neoplasm: Novel sc-seq findings demonstrate the functional differences in CAFs, with immunogenic subsets (e.g., PI16+/SLIT2+) promoting anti-tumor immunity and positive therapy response, while pro-tumor subsets (e.g., FAP+/CTHRC1+) drive ECM remodeling, immunosuppression, and invasion through pathways like WNT and TGF-β.