Next, total RNA was extracted from snap‐frozen left ventricular extracts and subjected to qRT‐PCR for transcript analysis; NonTg ChN (n = 6), NonTg Ch‐ (n = 6), 3xTg‐AD ChN (n = 4), and 3xTg‐AD Ch‐ (n = 6). This evidence concerns the gene C4B and Alzheimer disease.