CA9 and neoplasm: Other promising molecular biomarkers are B7-H3, chondroitin sulfate proteoglycan-4 (CSPG4), carbonic anhydrase-IX (CAIX), GD2, human epidermal growth factor receptor 2 (HER2), interleukin 13 receptor alpha 2 (IL13R α2), matrix metalloproteinase (MMP2), trophoblast-cell-surface antigen 2 (TROP2) and 1p/19q co-deletion [43,44], ATRX mutations [45], EGFR (epidermal growth factor receptor) alterations [46], CD70, CD147, CDKN2A deletions [47], exosomes [48], cfDNA (cell-free DNA) [49], ctDNA (circulating tumor DNA) [50], and CTCs (circulating tumor cells) [51].