FGF2 and neoplasm: Moreover, an ELISA showed that FGF-2, which is secreted by CAFs,12 was present in B16-F10 tumour lysates but not in lysates or conditioned medium of B16-F10 cells cultured in vitro (Supplementary Fig. 10), suggesting that CAFs in the tumour stroma are functional in terms of FGF-2 production.