Rare, deleterious, and druggable mutations were reported in many genes associated with cancer, including ALK, CDKN2A, KRAS, NOTCH1, TOP1 (topoisomerase 1), and TP53. Reported druggable mutations in highly expressed genes occurred in CDKN2A, KRAS, NOTCH1, and TP53. The gene discussed is TOP1; the disease is cancer.