PFKFB3 and familial dilated cardiomyopathy: The mass spectrogram of OPA1 is demonstrated in Fig. 4D. To validate the interaction between PFKFB3 and OPA1 in DCM, we conducted co-immunoprecipitation (Co-IP) assays using antibodies against PFKFB3 and OPA1 in the hearts of db/db mice (Fig. 4E).