In MPS I mice (a model of Hurler disease caused by alpha-L-iduronidase deficiency) both HS and DS accumulate and the mice have similar changes in microglial activation genes as MPS IIIb; however, genes associated with inflammation are not up-regulated (e.g. Ifitm1, Ifnar2 ) [58]. This evidence concerns the gene IDUA and Hurler syndrome.