WNT4 is a secreted protein that in humans is encoded by the Wnt4 gene, found on chromosome 1. It promotes female sex development and represses male sex development. Loss of function can have serious consequences, such as female to male sex reversal.
The WNT gene family consists of structurally related genes that encode secreted signaling proteins. These proteins have been implicated in oncogenesis and in several developmental processes, including regulation of cell fate and embryogenesis.
WNT4 is involved in a couple features of pregnancy as a downstream target of BMP2. For example, it regulates endometrial stromal cell proliferation, survival, and differentiation. These processes are all necessary for the development of an embryo. Ablation in female mice results in subfertility, with defects in implantation and decidualization. For instance, there is a decrease in responsiveness to progesterone signaling. Furthermore, postnatal uterine differentiation is characterized by a reduction in gland numbers and the stratification of the luminal epithelium.