When observed according to biological groups, patients belonging to groups with a worse prognosis (p-CLL and CLL-TFT) presented Ig G, while the stages of a better prognosis (MBL and c-CLL) presented Ig M. It should be noted that for the IGHV mutational status with a poor prognosis (U-IGHV), both isotypes of Ig were present compared to M-IGHV (in which the Ig M isotype was detected); therefore suggesting that this subset of patients had a high probability of virus reactivation. The gene discussed is GAN; the disease is B-cell chronic lymphocytic leukemia.