A study of 41 patients tracking ctDNA mutation frequency of 6 tumor driver genes (EGFR, KRAS, TP53, BRAF, PIK3CA, and ERBB2) within 10 days before and after surgical resection, also reported a ctDNA mutation frequency decreased from a median of 8.88 to 0.28%, with most reductions seen in patients with stage I disease (15). The gene discussed is PIK3CA; the disease is neoplasm.