Next, qRT-PCR analyses in 3 paired CLL patient samples (ibrutinib resistant #CLL 1, partial remission #CLL 2, and ibrutinib sensitive #CLL 3) pre- and post-ibrutinib treatment in the clinic revealed an increase in pten and foxo3a in #CLL 3 sample after ibrutinib treatment in contrast to #CLL 1 (Fig. 3c and d). This evidence concerns the gene FOXO3 and B-cell chronic lymphocytic leukemia.