The function of NDUFAF1 (NADH:ubiquinone oxidoreductase complex assembly factor 1, Ensembl gene identifier ENSG00000137806) is as follows. As part of the MCIA complex, involved in the assembly of the mitochondrial complex I. {ECO:0000269|PubMed:16218961, ECO:0000269|PubMed:17557076, ECO:0000269|PubMed:32320651}.