TP53 and lymphoma: Since Trp53-heterozygous mice display reduced lymphoma development and therefore increased life span, we went on to generate Ptprz1-deficient Trp53-heterozygous mice (Trp53+/-/Ptprz1-/-) and compared them to Trp53-heterozygous mice (Trp53+/-/Ptprz1+/+) and to Trp53-heterozygous mice lacking one Ptprz1 allele (Trp53+/-/Ptprz1+/-).