We measured the total amount of the fatty acids (FAs) C26:0, C24:0, C22:0 and, for normalization, C16:0 by using gas chromatography–mass spectrometry (GC–MS) in the following isolated cell types: monocytes (CD14+), granulocytes (CD15+), B cells (CD19+), NK cells (CD3−/CD56+) and T cells (CD3+) of controls and AMN patients (Fig. 3). The gene discussed is FUT4; the disease is adrenomyeloneuropathy.