XPO1 and B-cell chronic lymphocytic leukemia: Recently, the XPO1 gene has been found to be frequently overexpressed or mutated in CLL and affected by gain-of- function point mutations in 25–35% of RS, resulting in an unbalance between pro-oncogenic and antioncogenic proteins (i.e., p53) (Figure 1 and Figure 2) [123,124].