PPM1D and neuroblastoma: WIP1 is overexpressed in a variety of tumors, including neuroblastoma, breast cancer, ovarian cancer, pancreatic cancer, PCa, liver cancer, gastric cancer, colorectal cancer, thyroid cancer, medulloblastoma, and other tumors; also, WIP1 is closely related to the occurrence and development of breast, gastric, and pancreatic cancers [33].