MDM2 and undifferentiated pleomorphic sarcoma: miR-320a was first reported in 2014 to be highly associated with the development of leiomyosarcoma (LMS) and undifferentiated pleomorphic sarcoma (UPS), and the expression of potentially involved genes, including IMP3, ROR2, MDM2, CDK4, and UPA, was shown to be correlated with chromosomal modification and tumor development/progression of LMS and UPS [28].