human induced pluripotent stem cell (hiPSC)-derived primitive macrophages (hiPMs) and their conditioned medium (hiPM-CM) promote human cardiomyocyte proliferation and to enhance cardiac regeneration in infarcted adult mouse hearts. To identify the components underlying the pro-proliferative effects hiPM-CM, and the conditioned medium of hiPM precursors (hiPMpre-CM) were collected and the protein components were analyzed by mass spectrometry.