IL13RA2 and neoplasm: In view of this, we can distinguish so-called tumor-associated antigens (TAAs), ubiquitous non-mutated proteins that are upregulated in tumors compared to normal tissues (e.g., EGFR, IL-13Rα2, and gp100), and tumor-specific antigens (TSAs), produced and expressed only by tumor cells (e.g., EGFRvIII).