Based on previous evidence of neuroinflammation in the brains of early symptomatic Mcoln1−/− mice and the ability of cytokines to pass through the blood–brain barrier, we aimed here to establish peripheral cytokine profiles in MLIV patients and Mcoln1−/− mice and to test whether peripheral cytokines correlate with disease progression. The gene discussed is MCOLN1; the disease is mucolipidosis type IV.