Table 1.

Comparison of features between apoptosis, autophagy, necroptosis and ferroptosis

		Apoptosis	Autophagy	Necroptosis	Ferroptosis
Morphological features	Cell membrane	Plasma membrane blebbing; rounding-up of the cell	Lack of change	Rupture of plasma membrane	Lack of rupture and blebbing of the plasma membrane; rounding-up of the cell
	Cytoplasm	Retraction of pseudopods; reduction of cellular volume	Accumulation of double-membraned autophagic vacuoles	Cytoplasmic swelling (oncosis); swelling of cytoplasmic organelles	Small mitochondria with condensed mitochondrial membrane densities, reduction or vanishing of mitochondria crista, as well as outer mitochondrial membrane rupture
	Nucleus	Reduction of nuclear volume; nuclear fragmentation; chromatin condensation	Lack of chromatin condensation	Moderate chromatin condensation	Normal nuclear size and lack of chromatin condensation
Biochemical features		Activation of caspases	LC3-I to LC3-II conversion Substrate (e.g., p62) degradation	Drop in ATP levels	Iron and ROS accumulation Activation of MAPKs Inhibition of system Xc - with decreased cystine uptake GSH depletion and increased NAPDH oxidation Release of arachidonic acid mediators (e.g., 11-HETE and 15-HETE) Δψm dissipation
		Oligonucleosomal DNA fragmentation		Activation of RIP1, RIP3, and MLKL
		Δψm dissipation		Release of DAMPs (e.g., HMGB1)
		PS exposure		PARP1 hyperactivation
Inhibitors		Caspase inhibitors	Autophagy inhibitors (e.g. 3-MA, wortmannin)	Necrostatins (e.g. Nec-1)	Lipophilic antioxidants (e.g. Fer-1, vitamin E)
				Necrosulfonamide	Iron chelators (e.g. DFO, CPX)

Adapted from Xie Y et al. [6] and Cao JY, Dixon SJ [7].