PIK3CA and cancer: To confirm the clinical potential of the PIBEX chip for liquid biopsy, we used the Multiplex I cfDNA Reference Standard Set (Horizon Discovery, UK), which contains eight cancer-relevant mutations, including B-Raf proto-oncogene, serine/threonine kinase (BRAF), epidermal growth factor receptor (EGFR), Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), neuroblastoma RAS Viral (V-Ras) Oncogene Homolog (NRAS), and PIK3CA, at 5%, 1%, and 0.1% allelic frequencies in synthetic plasma.