Ecto-phospholipase that cleaves the phosphodiester bond in the glycosylphosphatidylinositol (GPI) anchor of TRABD2A and TRABD2B, releasing them from the plasma membrane. The release in the extracellular space inactivates these metalloproteases involved in the negative regulation of Wnt signaling. . This is the function of Ensembl gene identifier ENSG00000178795 (GDPD4, glycerophosphodiester phosphodiesterase domain containing 4).