I recall assisting in a gynaecology operation when we had delivery of amniotic membranes from our neighbouring obstetrics ward. These were used to line our operation patient's vaginal vault cavity as she had vulvovaginal cancer. The treatment was a success, although I had moved in my medical rotation and never found out if she was cured. All we wanted was a lining tissue to cover the raw wound surfaces to allow closure without deep internal suturing. There was thus no concern re allograft rejection. The surgeon, a Mr G Smart, believed that placental tissues were somehow protected from being rejected by the patient's immune cells. Pretty innovative thinking.