Quantification of fibroblast proliferation (left; n= 4 E16.5, P10; n= 3 E10.5, E18.5, P2, P21, P44, P50; n= 2 E17.5, P0 biological replicates) and collagen density (right; n= 4 E16.5, P2, P6, P10, P14, P16, P21, P50; n= 3 E10.5, E18.5, P2, P21, P44, P50 biological replicates) with age. 