Although the cross-sharing and inter-conversion makes it difficult to identify the exact pathway, metformin-treated mice showed increased expression of 15-LOX and 5-LOX, and, most interestingly, increased levels of RvE1 in the serum and increased expression of its receptor, ChemR23 [106], on tumor cells, in contrast to DHA-derived RvD1 and its receptor FPR2 [66]. This evidence concerns the gene FPR2 and neoplasm.