Microsomal epoxide hydrolase (MEH) is an endoplasmic reticulum enzyme expressed in most tissues of a broad range of species (Beetham et al., 1995; Coller et al., 2001) and was herein found to be only expressed in response to infection in R. sanguineus MG (UniProt ID: A0A224Z4E8). This evidence concerns the gene EPHX1 and infection.