It should be noted that the expression ‘apoptosis’ hides a major degree of biochemical and
functional heterogeneity. There are several distinct subtypes of apoptosis that, although
morphologically similar, can be triggered through different biochemical routes (for instance
through the ‘intrinsic’ or the ‘extrinsic’ pathway, with or without the contribution of
mitochondria, etc...).25,26 Moreover, the apparent uniformity of apoptotic cell death may
conceal heterogeneous functional aspects, for instance concerning the perception of apoptosis
by the immune system.27 Thus, although apoptosis mostly occurs in a non-immunogenic
fashion, some lethal stimuli can lead to the exposure or secretion of proteins that elicit the
engulfment of apoptotic material by dendritic cells, followed by efficient antigen presentation
and stimulation of a specific immune response.28