RB1 and diffuse large B-cell lymphoma: While gains of 1q, 11q and of chromosome 7 as well as 17p losses are present in both immunodeficiency related and immunocompetent DLBCL, deletions at 13q14 are usually absent (30, 57) suggesting a possible role in immune escape for the inactivation of MIR15/MIR16 or of RB1, whose loci on 13q are frequently co-deleted in DLBCL (69).