DDO and Duchenne muscular dystrophy: 2021). In this study, Ddo mRNA levels in the hippocampus of mdx mice were similar to those in wild‐type mice, following the expected expression pattern over time: E18, P10, and 6 to 7 weeks. Peroxisomal functionality has yet to be explored in either DMD patients or mdx mice (or other animal models); however, we cannot exclude the possibility that compromised DDO physiological activity may contribute to the D‐aspartate dysmetabolism observed in mdx mice.