LGALS4 and cardiomyopathy: In parallel OCT studies, cardiomyocyte-specific suppression of dMfn depressed heart tube contractions (compared to tincΔ4-Gal4 controls); this cardiomyopathy was rescued by concurrent expression of wild-type Mfn2, but not mutant M393I or R400Q Mfn2 at both 1 and 4 weeks (Figures 5d, 5e and Figure S1b).