CD22 and B-cell chronic lymphocytic leukemia: Moreover, we observed a positive correlation (R2 = 0.69; R = 0.83) between the CD22 transcript (by RNA-Seq) and the CD22 protein levels (by flow cytometry) for the patients with CLL (Fig. 1B), suggesting that the downregulation of CD22 expression in CLL B cells is likely regulated at the transactional level.