The CCK−/− mice, however, showed no increase in their freezing responses to the VS after HF-VS/EAC pairing (Fig. 4U; two-way ANOVA, F(4,64) = 2.073, p = 0.095; pairwise comparison, 2.22 ± 3.69% baseline vs 7.41 ± 6.91% at day 4, p = 1.000, n = 9). The gene discussed is CCK; the disease is hydrops fetalis.