Because it can be a modulator of MMP activity, we also examined the levels of β2M in serum and tissue of PCa patients at the time of prostatectomy to determine if a triad relationship might exist with perlecan and MMP-7 in well-characterized tissue specimens and sera that can offer prognostic indicators of PCa grade, invasion potential and likelihood of distant metastasis. Here, MMP7 is linked to posterior cortical atrophy.