Changes in the expression of astrocytic immunophenotypic markers were observed in PiD with presence of increased reactive GFAP+ astrocytosis10 in FTLD-tau overall and specifically in PiD, consistent with a previous study in a smaller cohort.60 Increased GFAP has been suggested to indicate astrocytic phenotypic changes rather than astrocyte proliferation,61 which is supported in our data by unchanged expression of ALDH1L1, a constitutive pan-astrocyte marker.62 The gene discussed is ALDH1L1; the disease is pelvic inflammatory disease.