In the present study, we discovered by JC-1 assay that knockdown of APOC1 resulted in a decrease of multimers (red) and an increase of monomers (green) in the mitochondria of DLBCL cells (Figure 2K–2M), demonstrating a decrease in the mitochondrial membrane potential and activation of the endogenous mitochondrial apoptotic pathway, which may be one of the causes of apoptotic cell death. The gene discussed is APOC1; the disease is diffuse large B-cell lymphoma.