Interestingly, 7 of the 11 GCB-DLBCL cell lines had complete loss of PTEN function, whereas all ABC-DLBCL cell lines expressed PTEN, suggesting that PTEN mutation may be related to PTEN loss in GCB-DLBCL [85] (Table 2). The gene discussed is PTEN; the disease is aneurysmal bone cyst.