SOX21 and neoplasm: Furthermore, regression analysis suggested excellent consistency of the expression abundance of the 3 prognostic-related lncRNAs between exosomes and tumor tissue, with 0.61 (P<0.001), 0.45 (P<0.001), and 0.51 (P<0.001) for HOTAIR, SOX21-AS1, and STEAP3-AS1, respectively, as illustrated in Figure 7C.