As ICAM1 has also been reported to be highly expressed in microglia [42], we measured the expression of the prototypical microglia marker, IBA1 and found ICAM1 was not correlated with IBA1 mRNA in controls (r = 0.20, p = 0.30) or schizophrenia (r = 0.13, p = 0.51). Here, ICAM1 is linked to schizophrenia.