CTLA4 and neoplasm: Several studies have identified promising predictive biomarkers for TKI therapy, including tumor-infiltrating neutrophils (27), tumor-infiltrating CD19(+) B lymphocytes (28), circulating CD45(dim) CD34(+) VEGFR2(+) progenitor cells (29), expression of HLA class I (30), Carbonic anhydrase 9 (31), Serum amyloid alpha (32), genetic polymorphism in CTLA-4 (33) and so on.