GSK3B and cardiac hypertrophy: Given the links between elevated collagen and GSK-3β, we next wanted to determine whether there would be an inactivation of GSK-3β, which results in cardiac hypertrophy and fibrosis in rodents when inactivated (phosphorylated at S9A) or knocked out.52,53 Interestingly, we saw a significant increase in the ratio of inactivated (phosphorylated) GSK-3β to total GSK-3β in the Δ9-THC-exposed groups (Fig. 3e).