RAC1 and osteosarcoma: In osteosarcoma cells, CaMKIIα increases the phosphorylation of T-lymphoma and metastasis gene 1 (Tiam1) and its membrane localization, and then activates ras-related C3 botulinum toxin substrate 1(Rac1), inhibits the expression of p21CIP/KIP and leads to a cell cycle progression [21].