These results indicate that the effects of PTEN levels on the invasiveness of circPTEN1 overexpressing or knockdown LoVo cells may be partially attributed to regulating the expression of Snail, and demonstrate that different family members of the PTEN gene, circPTEN1 and the PTEN protein, could both inhibit CRC metastasis, which highlights the complexity of the mechanism by which the PTEN gene exerts tumor-suppressor functions. The gene discussed is SNAI1; the disease is neoplasm.