Gene expression profiling of the main glutamine transporters by CD138⁺ cells. (A) Box plot distribution of the expression levels of SLC7A5 (LAT1), SLC1A5 (ASCT2), SLC38A1 (SNAT1), SLC6A14 (ATB^0,+), SLC7A11 (xCT), SLC38A3 (SN1), and SLC7A7 (y+LAT1) genes in a 323-sample dataset, including 18 healthy donors (N), 28 MGUS, 19 SMM, 200 ND-MM, 26 R-MM, 9 PCL patients, together with 23 HMCLs. This 323-sample dataset was generated using GSE13591, GSE6205, GSE6477, and GSE6691 dataset, profiled on GeneChip Human Genome U133A arrays. (B) Box plot distribution of the expression levels of the same Gln transporter genes shown in panel A plus SLC38A5 (SN2) in a 283-sample dataset, comprising 9 N, 20 MGUS, 33 SMM, 170 ND-MM, 24 primary PCL (PPCL), and 9 SPCL cases and also including 18 HMCLs. This 283-sample dataset was obtained using GSE66293 and GSE47552 dataset, analyzed on GeneChip Human Gene 1.0 ST array. For panels A and B, the significance of Kruskal-Wallis and Jonckheere-Terpstra tests was indicated.