The function of the mitochondrial protein CARD19 remains largely unknown. To begin to understand the molecular function of CARD19, we performed mass spectrometry-based proteomics to identify interacting partners of CARD19 in murine macrophages. We analyzed anti-MYC tag immunoprecipitates of 3xMYC-CARD19, expressed at approximately endogenous levels in raf-myc-immortalizd macrophages from a Card19-/- strain (Jackson Labs stock # 036463).