The induction of acute cardiac hypertrophy by daily repeated β-adrenergic administration of isoproterenol showed that ApoE-KO CF mice had a 12% decrease in HR (P < 0.001 vs. CF baseline) with a 12% increase in RR (P < 0.001 vs. CF baseline) and 11% increase in ST (P < 0.01 vs. CF baseline) intervals compared with ApoE-KO MR mice (Figure 3G). This evidence concerns the gene APOE and cystic fibrosis.