In this study, we discovered that TMEM100 overexpression could inhibit phosphorylation of Smad2 and Smad3, as well as the expression of TGF-β1 in CRC cells, but the inhibitory effect of TMEM100 overexpression on the progression of CRC cells could be reversed by overexpressing Smad2/Smad3. The gene discussed is TGFB1; the disease is colorectal carcinoma.