HOXA cluster antisense RNA 2 (HOXA-AS2), transcribed between the HOXA3 and HOXA4 genes, has been implicated in oncogenic promotion in pancreatic cancer, breast cancer [144,145], colorectal cancer [146], GC [147,148], bladder cancer [149], HCC [150], thyroid cancer [151], gallbladder carcinoma [152], lung cancer [153,154,155], osteosarcoma [156], glioma [157], and leukaemia [158,159]. This evidence concerns the gene HOXA-AS2 and osteosarcoma.