FOXP4 and posterior cortical atrophy: The results of silencing the FOXP4‐AS1 in the osteosarcoma cell lines were contrary to the results of up‐regulating FOXP4‐AS1.9 Studies by Wu et al indicated that FOXP4‐AS1 is significantly up‐regulated in PCa tumor tissues and overexpressed in tumor tissues of PCa patients with advanced stage.