Mice lacking the CI-MPR die at day 15 of gestation due to cardiac hyperplasia. The mice suffer from abnormal growth because they are unable to regulate the levels of free IGF-II (insulin-like growth factor type II).
Mice that lack the CI-MPR gene die prematurely, on day 15 of pregnancy, due to an abnormality in heart cell growth. As a result, these mice experience irregular development because they are unable to regulate the levels of IGF-II.