AKT1 and neoplasm: Moreover, FGD1 repression not only resulted in apoptotic cell death but also enhanced the growth-inhibitory effect of MK2206 in osteosarcoma tumor cell lines in vivo and in vitro (Figure 3F-3J, Figure S4B and S4C), which indicates that the PI3K/AKT pathway plays an important role in mediating the biological function of FGD1 in osteosarcoma cells.