HMGA2 and breast cancer: Pseudogene RPSAP52 positively regulates the transcription of HMGA2 in the nucleus and acts as a translational co-regulator with LIN28B and HMGA2 mRNAs in the cytoplasm to regulate the function of IGF2BP2 protein; RPSAP52 regulates the HMGA2/IGF2BP2/LIN28B axis through a double mechanism to show the oncogene characteristics in breast cancer, rhabdomyosarcoma, Ewing’s sarcoma and other human tumors [24].