Enzastaurin also reduced the phosphorylation of the downstream PKCβ-signaling pathway effectors Akt and GSK3β; these findings are consistent with several previous reports in different cancer cell lines, xenografts and peripheral blood mononuclear cells (PBMCs) (Graff et al, 2005; Querfeld et al, 2006; Rizvi et al, 2006), suggesting the use of GSK3β phosphorylation in PBMCs as a pharmacodynamic marker for enzastaurin (Graff et al, 2005). This evidence concerns the gene GSK3B and cancer.