To determine whether C3/ASP upregulation was functionally relevant in the obese phenotype of Par-4 knockout mice, we crossed C3-/- mice with Par-4-/- mice and tested the C3/Par-4 double knockout (DKO) mice (Figure S6A) for obesity on standard chow diet. Here, F2RL3 is linked to obesity due to melanocortin 4 receptor deficiency.