Updated project metadata. p21-activated kinase 4 (PAK4) is a serine/threonine kinase critical during development and with a proposed role in cancer and related cellular processes, including cell proliferation, survival and migration. However, while a limited number of PAK4-interacting proteins have been identified, the PAK4 interactome has not been systematically characterized. Here, we employed iTRAQ-based quantitative mass spectrometry of PAK4-immunioprecipitations from three distinct isolated cellular fractions to comprehensively profile the PAK4 interactome in human. These data will provide a valuable resource for further investigations on the role of PAK4 in physiology and disease.