According to MPEP 2304, an interference can be suggested by either an applicant or an examiner. Specifically, the MPEP states: "The suggestion for an interference may come from an applicant or from an examiner." This means that both parties involved in the patent application process have the ability to initiate the interference procedure if they believe there is a conflict in inventorship or priority. To learn more: interference suggestion patent examiner patent applicant MPEP 2304