TP53 and lymphoma: These alanine substituted p53 mutant mice developed an array of malignancies, thereby reinforcing a link between p53-dependent DDRs and tumor suppression.41 Another study also showed that mice with a single alanine substitution at Ser18 of p53, instead of developing early-onset spontaneous tumors like those found in p53 null mice, were succumbed to late-onset lymphomas, demonstrating that DDR function of p53 is important to tumor suppression in vivo.