Very long chain fatty acid synthetase (VLACS, or SLC27A2), an enzyme whose function is presumed missing in ALD, is highly expressed in liver and kidney, but is expressed at much lower levels in brain. However, brain contains high amounts of VLCFA and is the organ most affected in ALD. In an attempt to isolate a VLACS isoform with a different tissue distribution, Berger et al. (1998) used degenerate PCR to clone a mouse cDNA and a partial human cDNA encoding a VLACS-related protein, termed VLACSR. VLACSR is 43% identical to mouse VLACS and 37% identical to mouse FATP. Northern blot analysis of mouse tissues revealed that a 2.6-kb VLACSR mRNA was highly abundant in liver. Smaller VLACSR transcripts were present at low levels in brain, lung, testis, spleen, and skeletal muscle.