A recent study used a GJIC-incompetent Cx43 mutant to show that Cx43 GJIC is required for suppression of epithelial-to-mesenchymal transition (EMT) genes by osteosarcoma cells when cultured with osteoblasts, suggesting that heterocellular GJIC between these two cells types restrains metastatic potential [183]. The gene discussed is GJA1; the disease is osteosarcoma.