TMPRSS2 and cancer: The detailed mutation landscapes of these three genes were exhibited in Figure 4D. Furthermore, 3D crystal structures of mutation and protein styles of ACE2 (PDB 1R42), TMPRSS2 (PDB 1Z8G) and IFITM3 (PDB 1F5Z) were analyzed in Figure 4E. Database results also showed that these mutated genes could up-regulate their expression levels in cancers.