Zhang et al. observed that the enforced expression of Cx43 increased the protein level of the CDK inhibitor p27 in the osteosarcoma U2OS cells, they found no significant changes in the protein level of cyclin A, D1, E, CDK2, CDK4, CDK6, p15, p18 or p21 [35]. This evidence concerns the gene CCNA2 and osteosarcoma.