TP53 and neoplasm: In a proof-of-mechanism study of the nutlin-3a-derived drug RG7112 in operable WD/DDLPS, one partial response was seen in 20 treated patients, with best response of stable disease in 14 patients and progression in five.54 Comparison of pretreatment and post-treatment tumor samples showed up to a three-fold increase in p53 and p21 expression, with associated increases in tumor apoptosis.