The crucial role that biomarkers play in cancer research is becoming an increasingly foundational research area. Biomarkers demonstrate various biological environments, and understanding their function is critical to advancing cancer biology, diagnosis, and treatment. One class of biomarkers, spatially variable genes (SVGs), indicates genes that show variable expression between tumor regions. The tumor environment exhibits spatial heterogeneity, with genes within the tumor playing a crucial role in both tumor formation and cancer cell survival. Spatial transcriptomics, synthetic biology, and machine learning provide new ways to spot those special signatures. As tumor heterogeneity makes cancer react differently to treatments and creates challenges, studying SVG might contribute to treatment efficiency and enable a more effective individualized approach. Multidisciplinary experts from the fields of biology, medicine, genetics, and computer science closely link to the successful progress of biomarker identification and application in clinics.