Overexpression of REL has been associated to many lymphoid cancers such as primary mediastinal B-cell lymphoma, classical Hodgkin’s lymphoma, and solid tumors such as breast cancer, pancreatic cancer and head and neck cancer but not lung cancer.22, 38, 39, 40, 41 Interestingly, our lung cancer risk classifying locus harbored by the REL gene lies only 68 base pairs downstream of exon 6 and 17 base pairs upstream of exon 7, both of which are included in the REL homology domain. This evidence concerns the gene REL and breast cancer.