SIGLEC1 and post-transplant lymphoproliferative disease: SIGLEC1+ myeloid infiltrates were present in patients with glioblastoma (n = 2), herpes simplex encephalitis (n = 2) and cerebral infarction (n = 2), as well as toxoplasmosis (n = 1), cerebral abscess (n = 2) and post-transplant lymphoproliferative disorders (n = 1, PTLD, Fig. 2b).