CDKN1A and neoplasm: For example, Cdkn1a/p21 knockout animals are not prone to spontaneous tumor formation when monitored for their entire lifespan, and p21 loss has been found to be protective in radiation-induced thymic lymphoma [20,32], again emphasizing the distinct role of the Dino lncRNA transcribed from the shared Dino/Cdkn1a locus in tumor suppression.