Despite the benefits of improving teaching and learning that research evidences, professional learning communities (PLCs) can be challenging to sustain for a sufficient period of time to become deeply engrained within the school's culture and accepted by teachers as organizational norms. As PLCs strive to achieve a system-level reform and promote educators' reflective dialogues and shared experiences, they have strong potential to achieve positive changes in teacher perspectives and teaching practices focused on equity. Despite this potential, only a small number of studies have explored the potential of PLCs being used as vehicles to advance equity, and challenges educators can experience in translating PLCs' collaborative culture into advancing equity are under-researched. Therefore, employing Hord's (1997) attributes of PLCs as our conceptual framework, we conducted this study to understand how a middle school in the U.S. Midwest sustained its PLC to be deeply permeated in and accepted by the staff as a prevailing organizational culture. This study also aims to identify equity-related challenges educators experienced in the process. Data analysis identified school leaders' support for staff sense-making of the PLC and the promotion of security and vulnerability as the essential mindset for shared practice and innovation. We also found that issues around educational equity relevant to educator race, English Learners, and inclusive practices for students with special needs were limited and indeed need further development. Implications for school leadership practice and future research are provided in the discussion.