Biomarker
The 70 kDa ribosomal protein S6 kinase (p70S6K) is known to regulate cell growth by promoting protein synthesis and cell survival. mTOR (mammalian target of rapamycin) is a key kinase acting downstream of the activation of the phosphatidylinositol 3 kinase (PI3K). p70S6K is a well-characterized target of mTOR, of which the signaling pathway is frequently activated in human cancers and has recently been recognized as an important and attractive therapeutic target for cancer therapy.