PTEN and amyotrophic lateral sclerosis: Interestingly, PFN1 also binds to VCP [421], another ALS-related protein and regulator of autophagosome maturation, and PTEN [422] (phosphatase and tensin homolog), a phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase that dephosphorylates PIP3 tot PIP2 thereby also influencing the autophagy pathway.