Dai T, et al. - Given that, doublecortin-like kinase 1 (DCLK1) is considered a putative tumor stem cell (TSC) marker and a promising therapeutic target, as DCLK1⁺ progeny cells exhibit high expression in tumors, researchers sought to determine the biological function of DCLK1⁺ cells in tumorigenesis and tumor progression. They generated rabbit monoclonal antibodies (mAbs) against DCLK1, DCLK1-42, and DCLK1-87 mAbs. Using Western blot, they confirmed the specificity of two mAbs to DCLK1, which were bound to DCLK1-long in normal colon cells and to DCLK1-short in a cancer cell line as well as colorectal cancer (CRC) cells. Immunohistochemistry revealed more specificity of DCLK1-87 mAb vs a commercial anti-DCLK1 polyclonal antibody for DCLK1⁺ cell labeling. Overall, an efficient tool for the precise detection of DCLK1⁺ cells in cancer tissues was successfully generated. A protective role of high DCLK1 expression against tumor progression was suggested in CRC patients.