NOTCH2 and neoplasm: The mechanisms of tumor dormancy can be simply divided into the following two types: intracellular mechanisms represented by altered signaling pathways, including the p38 MAPK signaling pathway [42], TGFβ signaling [43], Wnt signaling axis [44], Notch2 pathway [45], etc., and extracellular mechanisms related to the tumor microenvironment, angiogenesis, and immunity.