PDE7B and B-cell chronic lymphocytic leukemia: PDE7B also has been found to have prognostic significance in a variety of cancers, such as chronic lymphocytic leukemia (CLL, high expression level of PDE7B acts as a bad prognostic factor)16, mantle cell lymphoma (high expression level of PDE7B is a poor prognostic indicator)17, glioblastoma (high expression level of PDE7B has a worse prognosis)18 and breast cancer (high expression level of PDE7B predicts poor prognosis)19.