Characterization of these Nav1.8Cre+/CB1flox/flox (Nav1.8-CB1−/−) mice in comparison to their littermate controls Nav1.8Cre−/CB1flox/flox (Nav1.8-CB1+/+) showed that they have a diminished weight gain and reduced food intake in response to HF diet challenge (Figure 6B). The gene discussed is CNR1; the disease is hydrops fetalis.