SMAD4 and neoplasm: Briefly, OLA1 inhibits the expression of TGFβ1, thereby inhibiting the phosphorylation of SMAD2, resulting in a decrease in the expression of SMAD4, inhibiting the expression of Snail and Slug, the important transcription factors of EMT, increasing E-cadherin, and achieving inhibition of the EMT pathway, which ultimately leads to a decrease in the metastatic ability of tumor cells.