TIMP1 and prostate neoplasm: As previously reported, both Ptenpc−/− and the Ptenpc−/−; Timp1−/− prostate tumors are characterized by the presence of both a proliferative and a senescent compartment, as detected by positivity to SA-β-Galactosidase (SA-β-Gal) staining and the expression of different senescence markers (Fig. 1a, Supplementary Fig. 1a)6,20.