On the 26^th of April, China National Intellectual Property Administration published the 2021 edition of the “Top 10 Patent Invalidation after Re-examination Cases”. Among the list was the lawsuit regarding the patent invalidation of “Novel left auricle occlude” as represented by Sunshine IP International and Beijing Yiju Law firm. The significance of this case lies in the redefinition of the term ‘Grace Period”, which set a precedent for future cases – patent holders should be obligated to disclose any leaks or misappropriations to the best of their knowledge.