Collect evidence and actively respond to lawsuits.

1. Collect evidence: Keep evidence of trademark cancellation, invalidation, and use evidence.

2. Actively respond to litigation: According to the provisions of the Trademark Law, if the Trademark Office revokes or declares a trademark invalid, it must be handled as a normal trademark infringement case. The parties concerned must actively respond to the lawsuit and collect relevant evidence, such as evidence of use, sales contracts, advertising evidence, etc., to prove the use of the trademark.