CD4 and neoplasm: The levels of the main methionine transporters of CD4 T cells, including SLC7A5 and CD988, which form a heterodimeric structure comprising SLC7A5 and SLC3A2, were not markedly reduced in tumor-infiltrated CD4 T cells compared to those in CD4 T cells from tumor-free mice (Supplementary Fig. 2h, i).