The function of MFF (mitochondrial fission factor, Ensembl gene identifier ENSG00000168958) is as follows. Plays a role in mitochondrial and peroxisomal fission (PubMed:18353969, PubMed:23530241, PubMed:24196833). Promotes the recruitment and association of the fission mediator dynamin-related protein 1 (DNM1L) to the mitochondrial surface (PubMed:23530241). May be involved in regulation of synaptic vesicle membrane dynamics by recruitment of DNM1L to clathrin-containing vesicles (By similarity). {ECO:0000250|UniProtKB:Q4KM98, ECO:0000269|PubMed:18353969, ECO:0000269|PubMed:23530241, ECO:0000269|PubMed:24196833}.