Phospho-p70S6K

The 70 kDa ribosomal protein S6 kinase (p70S6K) is known to regulate cell growth by promoting protein synthesis and cell survival. Mammalian target of rapamycin (mTOR) is a key kinase acting downstream of the activation of the phosphoinositide 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. Selection of patients based on the detection of activated p70S6K or AKT and/or loss of PTEN expression might help predict tumor cells’ sensitivity to rapamycin analogs.