The nuclear phosphoprotein p53 is an important regulator of cell proliferation in normal cells. Interestingly, the gene encoding p53 has usually undergone mutations in a wide range of tumor types. Recent studies of the p53 gene in Burkitt's lymphomas have demonstrated that mutations are extremely common, and in fact it is rare that both alleles of the p53 gene in these tumors are not inactivated by mutation or deletion. We present here genetic data regarding the status of the p53 gene in the Burkitt lymphoma cell line, Raji. As is typical for this type of tumor, both alleles have undergone point mutations. Further, statistical analysis of available data from a large number of Burkitt's lymphomas indicates an apparent tumor-specific distribution of p53 mutations. The possibility that specific mutations of the p53 gene may be important for different tumor types is discussed.