TP53 and cancer: Whilst the p53 protein encoded by TP53 has an important function in protecting cells from genomic and environmental insults, and in many cases is accompanied by nonsense and missense TP53 mutations that lead to functional loss of this protein [17], studies of CLL [16, 18], and other cancers [1, 8, 9, 12, 19], have shown that del17p is associated with adverse prognosis even in the absence of p53 dysfunction.