CELF1 and cardiomyopathy: To establish that the cause for the activation of the SRF transcription factor pathway is the change in CELF activity in MHC-CELFΔ mice and not secondary to the development of cardiomyopathy and heart failure, the consequences of CELF1 over-expression on the SRF pathway was examined in heart samples from a line of MCKCUG-BP1 mice that mildly over-expresses CELF1 in heart muscle, but does not develop overt cardiomyopathy [14].