The Mdm2 C305F mutation, which disrupts the binding of ribosomal proteins L11 and L5 to Mdm2 [11], causes an attenuation of p53 signaling, suggesting that the Mdm2 C305F mutation may alter the progression, rather than initiation, of prostate tumorigenesis in a similar way as p53 heterozygosity. This evidence concerns the gene MDM2 and male reproductive organ cancer.