4. Ibrutinib對某些淋巴惡性疾病如chronic lymphocytic leukemia, mantle cell lymphoma等非常有效。它的作用機轉為何？ (A) Phosphoinositide-3 kinase (PI3K) inhibitor (B) Burton tyrosine kinase (BTK) inhibitor (C) B-cell lymphoma 2 (BCL-2) inhibitor (D) Anti-CD79a monoclonal antibody (E) Anti-CD19 monoclonal antibody