Involved in the lipid remodeling steps of GPI-anchor maturation. Required for stable expression of GPI-anchored proteins at the cell surface. Interacts with PGAP2IP. Expressed in heart, brain, spleen, lung, liver, skeletal muscle, kidney and testis. In osteosarcoma cells, a chromosomal translocation with FGFR2 results in an in-frame fusion of the two genes. This generates FGFR2-ROS, a chimeric protein with transforming activity. Belongs to the PGAP2 family.