Moreover, these mice with moderately increased cardiac BBLN levels developed features of compensated heart failure at an age of 8 months, with a significantly reduced left ventricular EF of 40.5 ± 2.7% compared with 53.2 ± 4.5% of nontransgenic FVB mice, and showed a significant cardiac enlargement in echocardiographic examination (Extended Data Fig. 10a,b). Here, BBLN is linked to heart failure.