The proposed mechanisms of resistance include impaired immune synapse formation, reduced expression of CD19 on the surface of CLL cells, production of tumor-derived extracellular vesicles, and higher expression of transmembrane inhibitory receptors on T cells, such as CTLA-4, LAG3, and PD-1 [159,160,161,162,163]. The gene discussed is CD19; the disease is B-cell chronic lymphocytic leukemia.