Schematic overview of decarboxylation process by PSD to illustrate terminology: the left panel refers to the starting symmetric liposomes with 21 mol % in the outer and inner leaflet and, hence, as the total average. After decarboxylation, the total ≈ 14 mol %, inner-leaflet PS remained unchanged: ≈ 21 mol % (Δ ≈ 0), whereas outside PS was decarboxylated to ≈ 6 mol % (Δ ≈ −15). To see this figure in color, go online.