The invention belongs to the field of biomedicines, and relates to discovery and verification of the function of a new locus of carcinogenic related protein Smurf1. Mutation of the new locus causes complete loss of the protein function of the new site. A meaning is that the function of the activity of the Smurf1 as E3 ligase after mutation of the 69 locus of the protein Smurf1 can be reduced and then tumors can be inhibited. Furthermore, tumor study is expanded and perfected, and a new target locus is provided for tumor treatment and target drug development.