PF-4708671 is a highly specific inhibitor of p70 ribosomal S6 kinase (S6K1). PF-4708671 inhibits S6K1-mediated phosphorylation of S6 protein in response to IGF-1 (insulin-like growth factor 1), while having no effect on highly related RSK (p90 ribosomal S6 kinase) and MSK (mitogen- and stress-activated kinase) kinases.Form:Pale purple SolidMelting Point:189-191°CSolubility:DMSO, MethanolPfizer Compound