In particular, multiple studies have found that ERK phosphorylates Drp1 to promote mitochondrial fission in the context of septic cardiomyopathy,(48, 49), heart failure(50) and ischemia-reperfusion.(51) We found no evidence that Trm suppressed Drp1 phosphorylation (Supplemental Figure S6B) and multiple lines of evidence indicated that MEK inhibition decreased mitochondrial abundance (Figures 3D,E and Figure 4D,H), further arguing against accelerated fission. This evidence concerns the gene MAPK1 and heart failure.