Somatic mutation of the p53 tumor suppressor gene is the most common genetic alteration seen in human cancers, with >50% of adult human tumors bearing inactivating mutations or insertions, deletions in the P53 gene.  Wild type p53 prevents genetic instability and participates in the apoptotic response to radiotherapy and chemotherapy.  Mutations in P53 gene usually correlate with poor outcome and early recurrence in cancer.  This test provides important prognostic and prodictive information for patients with B-CLL, breast cancer, cervical cancer, melanoma or other cancers.