SLC2A1 and adenocarcinoma: Research has revealed that certain histopathological types of GC, such as SRCC and mucinous carcinoma, have lower 18F-FDG avidity than other adenocarcinomas due to relatively low expression levels of glucose transporter 1 (GLUT-1), a fewer number of active cancer cells, and high mucus-containing components 9, 11, 35, 53.