9.B.200 The 4 TMS TMEM255 or Pfam FAM70 (TMEM255) Family. 

The members of this family have sizes of 241 - 349 aas and exhibit 4 TMSs in a 3 + 1 arrangement. They are found only in eukaryotes. They exhibit an N-terminal region that has limited sequence similarity with members of the IncA (TC# 9.B.159) Family. Human TMEM255B, may act as a serous (cystic) neoplasm (SCN) marker (Watase et al. 2021).  Multidimensional comprehensive and integrated analysis of the potential function of TMEM25 in renal clear cell carcinoma with low expression status has been determined (Xi et al. 2024). At both the RNA and protein levels, TMEM25 displays a noteworthy downregulation in expression, which is consistently linked to an unfavorable prognosis. Receiver Operating Characteristic (ROC) curve analysis, univariate and multivariate Cox regression analyses confirmed the ability of TMEM25 to diagnose and determine prognosis in clear cell renal cell carcinoma (ccRCC). Its expression related closely with various immune cell types, immune checkpoints, immune inhibitors, and MHC molecules. Within ccRCC tissues, TMEM25 DNA methylation levels are observed to be elevated, and this upregulation is observed across various conditions. TMEM25 mutations also have an impact on the prognosis of ccRCC patients, and the results of drug sensitivity analyses are useful for clinical decision-making. Thus, TMEM25 in ccRCC could potentially function as a tumor suppressor gene, holding substantial promise as a novel biomarker for diagnosing, treating, and prognosticating ccRCC patients (Xi et al. 2024) .