SLC2A1 and neoplasm: Regarding the effect of GLUT1/6 on PDT, some researchers believe that the expression of GLUT1 promotes the enrichment of dendritic chlorin in mitochondria, thereby enhancing the effect of PDT (41), while others believe that highly expressed GLUT1 is the main reason for the poor effect of glycosylated photosensitizers in 3D tumor spheres (42).