MAPT and Alzheimer disease: Circularity of CD68-, CR3/43- and Iba1-positive microglia did not differ between the main FTLD subtypes and controls in any region (Fig. 6d–f) but all three FTLD subtypes had more circular CD68-positive microglia in TG compared with AD cases (Fig. 6d) and FTLD-tau cases had more circular CR3/43-positive microglia in FW compared with FTLD-TDP cases (Fig. 6e).