Tumor suppressor genes such as TP53, RB1, PTEN and APC are frequently inactivated in cancer. One common mechanism for tumor suppressor gene inactivation is the presence of nonsense mutation which introduces a premature termination codon (PTC) in the mRNA. The PTC prevents the ribosome from continuing translation as no aminoacylated-tRNA can bind in that position. Instead, release factors eRF1 and eRF3 are recruited and translation is terminated, leading to the release of a truncated and non-functional protein. The TP53 gene is mutated in around half of all human tumors. Around 10% of TP53 mutations are nonsense mutations. R213X is the most common TP53 nonsense mutation and the 6th most common TP53 mutation overall. One possible strategy for nonsense mutant TP53 rescue is induction of translational readthrough, as demonstrated for aminoglycoside antibiotics such as G418 and gentamicin. However, these antibiotics have severe side effects that limit their use in the clinics. In order to find novel nonsense mutant TP53 readthrough-inducing compounds, we performed an in silico screening using information at the National Cancer Institute database and identified the anticancer agent 5-Fluorouracil (5-FU) as a potential nonsense mutant TP53 readthrough inducer. Here we have confirmed the ability of 5-FU to induce translational readthrough of R213X nonsense mutant TP53. In addition, we demonstrate that full-length p53 protein in 5-FU-treated human tumor cells carrying R213X TP53 is functional as shown by upregulation of p53 target genes. We are currently examining p53-dependent biological effects of 5-FU as well as the mechanism by which 5-FU induces R213X translational readthrough. Our results suggest that patients with tumors carrying R213X nonsense mutant TP53 could benefit from treatment with 5-FU.