Among them, the mRNA expression levels of CMTM5 [normal tissues vs. breast cancer tissues, 45.36-fold (P = 1.44e−08)] and CMTM7 [normal tissues vs. breast cancer tissues, 3.72-fold (P < 1e−12)] were significantly downregulated, whereas those of CMTM1 (1.11-fold, P = 8.41e−12) and CMTM3 (1.02-fold, P = 3.43e−04) were only slightly upregulated and of CMTM2 (1.28-fold, P = 1.15e−02), CMTM6 (1.07-fold, P = 1.29e−02), and CMTM8 (1.03-fold, P = 1.90e−05) were only slightly downregulated in breast cancer tissues than in corresponding normal tissues (Figure 2). Here, CMTM6 is linked to breast cancer.