SPP1 and Infertility: Adenomyosis itself could cause infertility in a variety of approaches, including an enlarged uterine cavity, dysperistalsis of the uterus resulting in impaired sperm transport [23], the chronic inflammatory cells and inflammatory molecules caused by infiltration of ectopic endometrial glands [9], the increasing estrogen in eutopic endometrium caused by the overexpression of aromatase P450 [24], and alterations of endometrial receptivity-related molecules, such as osteopontin, integrin β3, leukemia-inhibiting factor, and the HOXA-10 gene during the implantation window [7].