The PI3K/AKT signaling pathway downstream of SHP2 can modulate T cell metabolism, especially glycolysis, which is important for CD8+ T cell effector function.[21, 29] As reported, PD‐1 and CTLA‐4 also inhibit glycolysis, thereby inhibiting T cell cytotoxicity and anti‐tumor immunity.[66] In addition, the fatty acid β‐oxidation (FAO) is increased in the presence of PD‐1 but not CTLA‐4.[66] Our data indicated that Siglec‐G impaired glycolysis in CD8+ T cells, but whether Siglec‐G affects FAO needs further investigation. Here, CTLA4 is linked to neoplasm.