Similarly, in a pan-cancer study incorporating colon, lung, gastric, and prostate cancer, tumour-specific mutations could be sporadically detected in CTCs as well as focal SCNAs in the MYC and PTEN genes in all CTCs which were only detected in minor fractions of tumour cells within the primary tumour, possibly indicating selection for metastases [99]. The gene discussed is PTEN; the disease is neoplasm.