PTEN is one of the most frequently deleted genes in various human cancer types [6], and alterations of PTEN were reported to have prognostic relevance in gastric cancer [7], colorectal cancer [8], non-small cell lung cancer [9], diffuse large B-cell lymphoma [10], mesothelioma [11] and prostate cancer [12]. This evidence concerns the gene PTEN and diffuse large B-cell lymphoma.