Apoptotic cells, via the activation of caspases, undergo significant proteome alterations. Phagocytosis of apoptotic cells by dendritic cells (DCs) leads to the processing of the apoptotic cell-associated (apoptotic) antigens and the cross-presentation of the resulting peptides on major histocompatibility complex class I molecules. This phenomenon seems crucial for inducing either cross-priming or cross-tolerance of CD8+ T cells, based on the presence or absence of various infectious or danger signals influencing the switch from tolerogenic immature DCs (iDCs) to mature DCs (mDCs) with high stimulatory and migratory capacities.