Thus, for example, analyzing CTCs from lung cancer patients in comparison with the original tumor and metastatic disease describes the appearance of mutations in genes involved in the response to cellular stress, such as Keap-1, Nrf2 and P300, which are key players in the Keap1-Nrf2-ARE signaling pathway and which could provide a survival mechanism for CTCs when they are in the process of distant tumor dissemination (116). Here, KEAP1 is linked to lung carcinoma.