Wang J, et al. – This research inspected the role of copy number (CN) and function of P–REX1 (PIP3–dependent Rac exchange factor–1) in cutaneous melanoma. The patient tumors and disease outcome analysis illustrated lower distant metastasis–free survival among AJCC stage I/II/III patients with high P–REX1 expression compared to patients with low P–REX1 expression. Hence, it was determined that P–REX1 played a significant role in tumor progression and served as a potential theranostic target.