A recent publication from the Ryan Lab has revealed that the complex I subunit exists in two isoforms. Published in FEBS Letters in December of 2016, the paper identifies a second long isoform of the peripheral N-module subunit NDUFV3 which exhibits tissue specific expression patterns.
A novel isoform of the human mitochondrial complex I subunit NDUFV3. Marris G. Dibley, Michael T. Ryan, David A. Stroud, FEBS Lett. 2016 Dec 17. doi: 10.1002/1873-3468.12527 Pubmed