PTEN and diffuse large B-cell lymphoma: However, in non-AR-DLBCL, Pfeifer et al. report 47% of GCB DLBCLs stained for PTEN in comparison to 87% in non-GCB DLBCLs leading to a proposal of PTEN loss that defines a PI3K/AKT dependent pathway in GCB DLBCL [19].