The EFRI-REM Catalyst team held mentoring summits to bring together EFRI-REM mentors to discuss current topics in mentoring and to provide support for mentors (faculty, and graduate students) implementing acquired mentoring skills. The workshop summits were held in Summer 2016 and 2017; there was an Entering Mentoring Train the Trainer two-day seminar. Core team members, who are also Entering Mentoring Certified Master Trainers, led the training efforts for the EFRI-REM PIs and graduate students. We also delivered elements based in cross-cultural mentoring and critical aspects of broadening participation of different groups in STEM in the Mentoring Webinar Series. The brainstorming exercise yielded several items as elements to be considered for cross-cultural mentoring and issues of invisibility. Future Train-the-Trainer workshops will occur for EFRI-REM mentors at all levels in the research continuum.