Measurement of total iron content (Fe2+ and Fe3+) in the unperfused brain by inductively coupled plasma mass spectrometry (ICP-MS) showed no statistically significant differences in total iron levels between Mcoln1−/− and wild-type mice, which rules out systemic iron deficiency in Mcoln1−/− mice (Fig. 6D). This evidence concerns the gene MCOLN1 and nutritional disorder.