Abstract: Abstract: Kringle-containing transmembrane protein 2 (Kremen2) is an important regulator in the classical Wnt signaling pathway. Originally, Kremen2 was only recognized as a suppressor of this signaling pathway. The subsequent research found that it plays a role in promoting the activation of Wnt signaling pathway in certain biological environments. In the regulation of the pathway, Kremen2 needs to interact with a variety of other protein regulators to participate in embryonic development, bone formation, tumorigenesis and other physiological and pathological processes. The discovery of protein Kremen2 and its molecular structure, its main interaction factors and protein functions are reviewed here, with related research prospects being put forward.