After its initial description as a novel phorbol-12-myristate-13-acetate-responsive gene in adult T-cell leukemia, Noxa was rediscovered in a differential display approach using mRNA from γ-irradiated wild-type and IRF-1/p53 double-deficient mouse embryonic fibroblasts.82 Like Puma, Noxa was initially identified as a primary p53-response gene. The gene discussed is TP53; the disease is T-cell leukemia.