CMTM5 and breast cancer: With regard to the immunohistochemical staining of CMTM5, among the 11 breast cancer patients with pertinent data in the Human Protein Atlas, only one (9.1%) showed low expression of CMTM5, whereas no expression of CMTM5 in tumor tissues was observed in the other 10 (90.9%) patients (Figures 7A,B).