IRX4 and posterior cortical atrophy: Interestingly, it was found that the IRX4-derived micropeptide IRX4_PEP1 promotes the proliferation, migration and invasion of prostate cancer cells by interacting with heterogeneous nuclear ribonucleoprotein K. Not only that, IRX4_PEP1 plays an important role in regulating PCa stem cells and chemotherapy resistance, suggesting its potential as a therapeutic target for PCa [125].