Nulligravid infertile women, a fertile control group and unrelated control group were screened for LIF gene mutations. 3 point-mutations were identified in the infertile group that reduced biological activity of the LIF protein. They concluded that a heterozygous LIF mutation could result in decreased availability of LIF in the uterus, leading to implantation failure and thus infertility. The gene discussed is LIF; the disease is Infertility.