By analyzing TCGA data in the GEPIA database, we found that the expression levels of multiple SLC38A family members (including SLC38A2, SLC38A4, SLC38A5, SLC38A6, SLC38A7, SLC38A8, SLC38A9, and SLC38A10) were significantly upregulated in GC tumor tissues (Fig. S1). Here, SLC38A9 is linked to gastric cancer.