To verify whether dimerization did not affect the binding of the FGF2 variants to the cellular pool of FGFRs, we analyzed the activation of FGFR-dependent extracellular signal-regulated kinase ERK1/2 pathway in NIH3T3 fibroblasts and U2OS osteosarcoma cells stably transfected with FGFR1 (U2OS-R1) upon a 15 min treatment with the individual dimers [3]. The gene discussed is MAPK3; the disease is osteosarcoma.