By the use of a compound mouse model with Pten and Sag conditional knockout alleles (Ptenfl/fl;Sagfl/fl) in which Pten and Sag deletion occur concomitantly upon Cre expression driven by specific Pb4 promoter in prostate epithelial cells, we showed that Sag inactivation remarkably inhibits prostate tumorigenesis, induced by Pten loss, as evidenced by delayed disease progression (Fig. 1f & g), and reduced proliferation of cancer cells (Figs. 1i & j and Additional file 1: Figure S1A&B). Here, PTEN is linked to cancer.