By analyzing the mRNA expression of SLC1A5, SLC3A2, and SLC7A5 in human colon cancer samples deposited in The Cancer Genome Atlas (TCGA) database (n = 41 matched pairs of normal and colorectal cancer samples) (Supplemental Table S1), we found that all three genes had elevated expression in nearly all patients (Fig. 3A). Here, SLC7A5 is linked to colorectal cancer.