Quantification of neprilysin specific activity in HEK293 transfected cells. Neprilysin specific activity is significantly higher in the HEK293 cells transfected with NEP-n in the cell lysate/membrane fraction compared to NEP-m, NEP-s, and GFP transfected cell lysates. NEP-s transfected cell lysates showed significantly higher NEP activity compared to NEP-m and GFP expressing cells. In the cell media from NEP-s transfected cells, NEP activity was significantly greater than all other transfected cell groups (NEP-m, NEP-n, and GFP). The asterisk (*) indicates significance with a p-value < 0.05. The number (#) indicates significance with a p-value < 0.001. Note differences in Y axis scaling for each panel.