PTEN and diffuse large B-cell lymphoma: According to the Pfeifer et al. study, deregulation of the PI3K/AKT pathway by PTEN loss was detectable almost exclusively in 55 percent of GCB-DLBCL cases but only in 14 percent of non-GCB-DLBCL cases and poor prognosis in 248 primary DLBCL patients [97].