APP and ovarian serous tumor: Many related studies have examined how these DEGs affected the formation of serous ovarian tumors, such as tyrosine kinase related DEGs (PTK2B, KIT, and SRC) [74,75,76], crucial factors known to be related to tumorigenesis (AKT1, MTOR, MAPK3) [64,77,78,79,80], DEGs related to cellular metabolism and immunity (EDN1, IL1B, INS, APP, LEP) [29,56,60,81,82,83,84,85,86], and agents for signal transmission and channels of cell membranes (CDK5 and ATP1B1) [59,87,88].