For example, CLL/SLL cells are positive for CD5, CD23, CD200, dim for CD20 and CD81, and negative for FMC-7 [37]; in MCL, lymphoma cells are positive for CD5, and negative for CD23 [38, 39]; and in FL, lymphoma cells are positive for CD10 and CD20, and negative for CD34 and TdT [33, 40]. The gene discussed is CD81; the disease is B-cell chronic lymphocytic leukemia.