FEZF1 and osteosarcoma: FEZF1-AS1 has been shown to be up-regulated in tumor tissues and cells, and exert oncogenic effects on lung cancer [18–21], breast cancer [22], liver cancer [23,24], gastric cancer [25–27], colorectal cancer [28,29], pancreatic cancer [30,31], ovarian cancer [32], cervical cancer [33], osteosarcoma [34], nasopharyngeal carcinoma [35] and multiple myeloma [36].