The study describes a novel approach to develop molecular probes for cancer diagnosis and biomarker discovery using cell-based aptamer selection. The researchers used a cell-based selection process, called cell-SELEX, to identify aptamers that specifically recognize molecular differences between cancer cells and normal cells. The selected aptamers have high affinity and specificity, binding to target cells with equilibrium dissociation constants (Kd) in the nanomolar-to-picomolar range. These aptamers can distinguish target cells from normal cells in mixed samples and identify cancer cells closely related to the target cell line in clinical specimens. The cell-SELEX method is simple, fast, reproducible, and does not require prior knowledge of target molecules, making it a promising tool for developing specific molecular probes in cancer research and diagnosis.The study describes a novel approach to develop molecular probes for cancer diagnosis and biomarker discovery using cell-based aptamer selection. The researchers used a cell-based selection process, called cell-SELEX, to identify aptamers that specifically recognize molecular differences between cancer cells and normal cells. The selected aptamers have high affinity and specificity, binding to target cells with equilibrium dissociation constants (Kd) in the nanomolar-to-picomolar range. These aptamers can distinguish target cells from normal cells in mixed samples and identify cancer cells closely related to the target cell line in clinical specimens. The cell-SELEX method is simple, fast, reproducible, and does not require prior knowledge of target molecules, making it a promising tool for developing specific molecular probes in cancer research and diagnosis.