SLC1A5 and neoplasm: The successful development of BLGLN addresses the current technological deficiency in optical imaging methodologies for accurate tumor glutamine uptake assessment, presenting significant application potential: 1) providing a robust analytical tool for tumor glutamine metabolism research; 2) facilitating high‐throughput screening of ASCT2 inhibitors; and 3) serving as a foundational design for developing advanced optical probes with enhanced signal‐to‐noise ratios and tissue penetration for tumor glutamine uptake monitoring.