The circulating tumoral biomarkers in the blood are the object of numerous researches for several decades. The potential clinical interests of these circulating biomarkers are diagnostic, prognostic, predictive of the efficiency of targeted therapies (according to the mutational profile of the cancer), and could allow the study of the mechanisms of resistance under process. In the multiplicity of these blood potential biomarkers joins a permanent evolution of the technological means used to detect them/to quantify, as well as to estimate their clinical utility.