Protein biomarkers including carbonic anhydrase IX (CAIX), a specific marker for clear cell renal carcinoma, show expression levels in TDEVs that correlate with tumor burden and response to therapy (Mallouk et al., 2023); proteins such as HIF-1α and VEGF in TDEVs also exhibit expression patterns associated with tumor progression and angiogenesis (Beekman et al., 2019). Here, CA9 is linked to neoplasm.