Caspase-2 is well characterized as a tumor-suppressor gene in various mouse cancer models,3, 4, 5, 6, 7 whereas loss of Pidd1 leads to a delayed tumor onset upon c-Myc overexpression.4 Our data demonstrate that loss of Raidd has no influence on the development of radiation-induced thymic lymphomas or chemically induced fibrosarcomas (Figure 1). This evidence concerns the gene MYC and fibrosarcoma.