TP53 and neoplasm: The overall PIK3CA mutation rate was 23% (35.4% in tumor tissue, 11.5% in ctDNA), 41% for TP53 (50% in tumor tissue, 32.7% in ctDNA), and 7.0% for ERBB2 (8.3% in tumor tissue, 5.8% in ctDNA) (Table 2).