Through advanced microengineering and nanotechnology, we have developed a proprietary microfluidic-based liquid biopsy device, the RUBYchip™ (PCT/EP2016/078406). This technology allows for the isolation of all types of CTCs, keeping them viable and enabling the analysis of their phenotypic, genetic and functional characteristics, enabling unprecedented frequent monitoring of cancer progression in a minimally invasive and cost-efficient way. Our chip isolates 70% of the very scarce CTCs from a 7.5mL blood sample of a cancer patient in less than 3 h and without the need of sample pre‐processing. This dramatic improvement in the sensitivity compared to competition is enabled by a unique microfilter network embedded in a microfluidic device that separates the CTCs from the healthy cells based on their size and deformability. Furthermore, the RUBYchip enables automation reducing inter-laboratory and inter-user dependence and ensuring reproducible analysis of CTCs.