CMTM4 and hepatocellular carcinoma: It has been found that CMTM family members are extensively involved in tumor development, with CMTM2, CMTM3, CMTM4, CMTM5, and CMTM7 abnormally expressed in HCC tissues and associated with the survival time of HCC patients, which are important factors that affect the prognosis of HCC patients [6,7,8,9,10].