C. Representative immunofluorescence staining of Lamp1 (red) in RCS chondrocytes treated with vehicle (5% ABS), FGF18 (50 ng/mL; 16 hours) and Actinomycin (1μg/mL; 4 hours). Nuclei were stained with DAPI (blue). Scale bar 10 μm. Representative images of N=3 biological replicates. Scale bar 10 μm. 