ACADVL and pancreatic ductal adenocarcinoma: In the lipid-abundant TME areas of pancreatic ductal adenocarcinoma, CD8+ T cells down-regulate the expression of very-long-chain acyl-CoA dehydrogenase (VLCAD) and promote the accumulation of long-chain fatty acids (LCFAs), finally impairing mitochondrial function and inducing cellular dysfunction (Fig. 1) [37].