“…However, recent studies show that there are resident immune cells in the Fallopian tube even in the absence of infection [ 3 , 33 , 34 , 35 , 36 , 37 ]. Immunohistochemical, fluorescent-activated cell sorting (FACS), and single-cell RNA-sequencing (scRNA-seq) analyses reveal that immune cells in both innate and adaptive immune responses are present in human Fallopian tubes [ 3 , 33 , 34 , 35 , 36 , 37 ]. Leukocytes (expressing PTPRC, also known as CD45) are the most abundant in human Fallopian tubes compared to other reproductive tissues.…”