PIK3CA and non-small cell lung carcinoma: Interestingly, the most frequently mutated gene in both plasma-cfDNA and CTC-derived DNA, as well as in FFPE, was the PIK3CA gene, which was suggested to be one of the subclonal driving alterations in early-stage NSCLC tumors by Jamal-Hanjani et al. [33] using multi-region whole-exome sequencing.