In this interview with Andrew Armstrong, MD, of Duke University, Durham, NC, speaking from the 2018 American Society of Oncology (ASCO) Annual Meeting, held in Chicago, IL, discusses how to best catch and diagnosis osteomimicry in metastatic castration-resistant prostate cancer (mCRPC). Dr Armstrong talks about how the osteoblast-like prostate cancer cells express high levels of alkaline phosphatase (AP), which could be used as a biomarker in the blood. Patients with high AP levels have responded better to treatment; however, this technique would need to be refined and adapted for clinical use.