MTOR and rhabdomyosarcoma: For instance, Ewing sarcoma and medulloblastoma cells were more sensitive to PKI-179, a phosphoinositide-3-kinase/mammalian target of rapamycin (PI3K/mTOR) inhibitor, while rhabdomyosarcoma cells were more sensitive to cobimetinib, a mitogen-activated protein kinase (MEK) inhibitor (Figure 6F).