PIK3CA and neoplasm: Similarly, when Janku et al. compared the mutational status of BRAF, EGFR, KRAS, and PIK3CA in plasma cfDNA samples to biopsy tissue samples, most mutations that were detected in the tumor biopsy samples were detected in plasma cfDNA samples: the concordant cases reached 91% for BRAF mutations, 99% for EGFR mutations, 83% for KRAS mutations, and 91% for PIK3CA mutations [26].