P70 ribosomal S6 kinase (S6K1) is a serine/threonine kinase which is activated by insulin and growth factors through PI3K and mTORC1 signaling pathways. PF-04708671 is a specific, cell-permeable inhibitor of S6K1 (IC50 = 160 nM). It does not inhibit S6K2, MSK, or RSK, or many other unrelated kinases, under conditions in which it inhibits S6K1 activity. It is useful in evaluating the role of S6K1 and, indirectly, mTORC1, in cell signaling.
