PIK3CA and colorectal carcinoma: Single cell array comparative genomic hybridization (CGH) and parallel sequencing of 68 CRC-associated genes confirmed the presence of driver mutations in genes such as APC, KRAS or PIK3CA in the primary tumour, metastasis and corresponding CTCs from two patients.55 However, certain mutations were only visible in CTCs, probably due to their low frequency in the primary tumour and metastatic deposits.55 These results suggest that liquid biopsy in patients with CRC is highly promising strategy to monitor tumour genomes in real time and facilitate personalised therapy.