An unexpected observation from large-scale cancer sequencing efforts was the relative rarity of high frequency, recurrent somatic mutations in common solid tumors.12 In total, 37% of breast cancers carry somatic mutations in TP53 and 36% in PIK3CA, the two most-frequently mutated genes, while most cancers display a variable assortment of low-frequency mutations in unique combinations. The gene discussed is TP53; the disease is cancer.