At Day 60 of differentiation, hiPSC‐derived astrocytes from all control and ALD lines were examined for typical astrocytic morphology and expression of the astrocyte‐associated markers GFAP, S100β, NESTIN, ID3, SOX9, and CD44 (Figures 1A and S2). This evidence concerns the gene S100B and X-linked adrenoleukodystrophy.