Human fibroblasts induce collagen lattice contraction in a similar manner as murine firoblasts. A. Means and 95% confidence intervals for collagen lattice areas as observed over seven days are given for primary cultures from human fibroblasts treated with lithium, Dkk-1, TGF-β, or a carrier. There is a statistically significant difference for TGF-β treatment compared to carrier after day three. For lithium treatment there is a statistically significant difference for the time points with an asterisk above the data points. B. Representative photographs of the collagen lattices at day five.