In contrast, the expression of PGK1 in Teff cells (CD-C3-GNLY, CD8-C3-CX3CR1) was low, suggesting that the glycolysis of Teff cells might be inhibited by the scarce available carbohydrates in TME, the potential reason being that the proliferating tumor cells consume a large amount of nutrients in the microenvironment, resulting in a lack of sufficient nutritional substrates for immune cells to activate the glycolysis process to proliferate and kill tumor cells [58]. Here, C3 is linked to neoplasm.